FC Carolinas - Broxton Civil Design Calculations_2017-12-28

Page 1 of 138
TABLE OF CONTENTS

PROJECT NARRATIVE Page 3 -4

STORM DRAINAGE CALCULATIONS Pages 5-28
· RAINFALL INTENSITIES TABLE Page 6
· SURFACE FLOW RUNOFF HYDROLOGY CALCULATIONS Page 7
· STORM DRAINAGE PIPE CALCULATIONS Page 8
· FLARED END RIP RAP SIZING Pages 9-12
· H/W NOMOGRAPH (FES 1A) Page 13
· DROP INLET CALCULATIONS Pages 14-17
· SWALE CALCULATIONS Pages 18-28

EROSION CONTROL CALCULATIONS Pages 29-36
· SEDIMENT BASINS CALCULATIONS Pages 30-33
· SKIMMER SIZING CALCULATIONS Pages 34-35
· TEMPORARY DIVERSION DITCH Page 36

BMP CALCULATIONS Pages 37-138
· PROJECT NARRATIVE & SUMMARY Pages 38-40
· BMP WETPOND CALCULATIONS Pages 41-42
· CONCRETE ANCHOR ANTI-FLOTATION CALCULATION Page 43
· NARRATIVE Page 44
· POND PACK CALCULATIONS Pages 45-134
· OUTLET STRUCTURE CALCULATION Page 135

DRAINAGE AREA MAPS Pages 136-138

· STORM DRAINAGE MAP Page 136
· PRE-DEV. DRAINAGE AREA MAP Page 137
· POST-DEV. DRAINAGE AREA MAP Page 138

Project Narrative

Project Description
The project site is located in Town of Waxhaw, Union County, N.C. and is an approximately 61 acre parcel along
Old Waxhaw Monroe Road (S.R. 1111). The proposed project consists of a recreation facility and driveway
connection to Old Waxhaw Monroe Road in accordance with NCDOT requirements. The project area drains to
Waxhaw Creeks and is subject to the site specific Water Quality Management requirements prescribed by the
N.C. Division of Water Quality (NCDWQ) as outlined in the regulations for the Goose Creek Watershed.

NCDWQ requirements that have been met in the design of this project include the control and treatment of the
difference in the stormwater runoff from the pre-development and post-development conditions for the one-year,
24-hour storm, with structural stormwater controls that promote infiltration of flows and groundwater recharge, if
practicable based upon soil conditions.

The rainfall amounts used in the analysis of this project were obtained from Charlotte-Mecklenburg Storm Water
Design Manual.

Structural stormwater controls have been provided to meet the following minimum requirements:

a. Remove an 85 percent average annual amount of Total Suspended Solids
b. Draw down the treatment volume no faster than 48 hours, but no slower than 120 hours, for detention
ponds.
c. Discharge the storage volume at a rate equal or less than the pre-development discharge rate for the
one-year, 24-hour storm.
d. Meet design of Stormwater Management Measures set forth in 15A NCAC 02H .1008.

Additional stormwater management measures have been provided for this project as required by Town of
Waxhaw to include the following:

a. In accordance with Section 3.1.3 of the Town of Waxhaw Stormwater Design Manual, the post
developed discharge rate at the property boundary is less than or equal to the pre development rate
for the (2 & 10) two and ten year storm events.

Natural Resources Inventory
The parcel is covered in approximately 65% woods and 35% grass fields. Soil & Forestry Services of the
Carolinas, PA (S&FS) has performed a stream/wetlands delineation/study and confirmed with the U.S. Army
Corp of Engineers and N.C. Division of Water Quality that an existing on-site wetland and two streams which
intersect the property are considered Waters of the State (Reference Wetland JD Dated 3/12/15 per attached in
appendix A)

Existing on-site slopes range from 2 to 20 percent on average and existing soil types on site is predominantly
Georgeville Silty Clay Loam (Hydrologic Group B). Soil & Forestry Services of the Carolinas, PA (S&FS) has
performed on-site geotechnical testing to establish soil suitability for proposed stormwater BMP construction, as
well as establish hydraulic conductivity of on-site soils for suitability for infiltration devices along with the vertical
location of Seasonal High Water Tables at the locations of the proposed BMP 1.

Existing and Proposed Drainage Patterns
Proposed drainage patterns to the proposed on-site BMP maintain existing drainage patterns to the maximum
extent practicable as need to create a balanced distribution of storm water flow thru BMP 1 in a consistent
manner with existing flows.

Page 3 of 138
Proposed BMP #1 (Wet Pond)
BMP #1 (Wet Pond) has been designed per the NCDENR requirements of the contributing drainage area
(18.81 ac.) to meet 85% TSS removal, 25% TN and 40% TP removal targets. The hydraulic conductivity of the
existing soils at the location of BMP #1 are 0.17 cm/hr (0.0688 in/hr) and do not support infiltration measures.
Additionally, the SHWT was established as required to establish the minimum vertical separations as outlined by
the NCDENR and DWQ requirements. BMP #1 meets or exceeds the following requirements:

• The control and treatment of the difference in the stormwater runoff from the pre-development and post-
development conditions for the one-year, 24-hour storm.
• Removal of an 85 percent average annual amount of Total Suspended Solids (85% TSS removal), 25%
TN (min) and 40% TP (min) removals
• Draw down the treatment volume no faster than 48 hours, but no slower than 120 hours.
• Discharge the storage volume at a rate equal or less than the pre-development
discharge rate for the one-year, 24-hour storm
• Meet design of Stormwater Management Measures set forth in 15A NCAC 02H .1008.
• The post developed discharge rate at the property boundary is less than or equal to the pre-development
rate for the (2 & 10) two and ten year storm events.

Page 4 of 138

FC CAROLINAS SOCCER COMPLEX

WAXHAW, NORTH CAROLINA

STORM DRAINAGE CALCULATIONS

Note: Refer to Construction Document sheet C2.0 for drainage area maps.

Page 5 of 138
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HYDROLOGIC CALCULATIONS FOR CLOSED STORM SYSTEM DRAINAGE DESIGN
FC Carolinas Soccer Complex NOTE: 10‐YR. INTENSITY OF 7.03 USED FOR CLOSED DRAINAGE SYSTEM AND
8.21 USED FOR 25‐YR INTENSITY IN CULVERT AND ROAD CROSSING  LOCATIONS.
Storm Drainage Hydrology
Structure
Drainage 
Area (acres)
Accumulated 
Drainage Area 
Runoff 
Coefficient Intesity Flow (cfs)
Accumulated 
Flow (cfs)
Contributing 
Structure
Network #1
FES 1A 2.02 2.02 0.70 8.21 11.61 11.61
DI 2H 0.77 0.77 0.30 7.03 1.62 1.62
DI 2G 0.32 1.09 0.30 7.03 0.67 2.30 2H
DI 2F 1.2 2.29 0.30 7.03 2.53 26.39 2G & 3A
DI 2E 0.53 2.82 0.30 7.03 1.12 27.51 2F
DI 2D 0.56 3.38 0.30 7.03 1.18 40.84 2E & 4A
DI 2C 1.16 4.54 0.30 7.03 2.45 43.29 2D
JB 2B 0 4.54 0.30 7.03 0.00 66.19 2C & 5A
FES 2A 0 4.54 0.30 7.03 0.00 66.19 2B
DI 3A 4.15 4.15 0.40 8.21 13.63 21.56 (FUTURE)
DI 4A 1.85 1.85 0.80 8.21 12.15 12.15
DI 5E 0.55 0.55 0.30 7.03 1.16 1.16
DI 5D 0.31 0.86 0.30 7.03 0.65 1.81
DI 5C 0.22 2.78 0.30 7.03 0.46 10.05 5D & 6A
DI 5B 1.17 3.95 0.80 7.03 6.58 16.63
DI 5A 1.09 5.04 0.82 7.03 6.28 22.91
CB 6A 1.70 1.70 0.65 7.03 7.77 7.77
FUTURE 1.38 1.38 0.70 8.21 7.93 7.93
Page 7 of 138
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IMaximum Tailwater Condit II d (in.) Q (cfs)IFES 1B 24 11.61 »IIFES 2A 36 66.19 » 23'L x 12'W x 18"D CLASS B APRONDescription of Apron10'L x 8'W x 18"D CLASS B APRONP:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\STORM DRAINAGE\16240-fes.xlsPage 9 of 138
THE ISAACS GROUP
FLARED END SECTION RIP RAP APRON DESIGN
FC CAROLINAS SOCCER COMPLEX
UNION COUNTY, NORTH CAROLINA
Maximum Tailwater Conditions
D = OUTLET PIPE DIAMETER (in)
Do =OUTLET PIPE DIAMETER (ft)
La = LENGTH OF APRON (ft) [FROM FIGURE 8-2, CHARLOTTE STORMWATER DESIGN MANUAL] (MINIMUM La = 10)
W = WIDTH OF APRON (ft) [W = Do + 0.4 La]
Q = FLOW (cfs)
d50 = STONE SIZE (ft) [FROM FIGURE 8-2, CHARLOTTE STORMWATER DESIGN MANUAL]
FES 1B FES 2A
D 24 36
Q 11.61 66.19
Do 23
3Do 69
La 10 23
W 6 12.2
d50 0.5 0.5
*MIN. APRON SIZE NOT TO BE LESS THAN 8'Wx10'Lx18"D CLASS B APRON
Page 10 of 138
1Minimum Tailwater Conditions d (in.) Q (cfs) 1BMP OS#1 30 14.46 »»»»»Description of Apron16'L x19'W x 18"D CLASS B APRONP:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\STORM DRAINAGE\16240-fes.xlsPage 11 of 138
THE ISAACS GROUP
FLARED END SECTION RIP RAP APRON DESIGN
FC CAROLINAS SOCCER COMPLEX
UNION COUNTY, NORTH CAROLINA
Minimum Tailwater Conditions
D = OUTLET PIPE DIAMETER (in)
Do =OUTLET PIPE DIAMETER (ft)
La = LENGTH OF APRON (ft) [FROM FIGURE 8-1, CHARLOTTE STORMWATER DESIGN MANUAL] (MINIMUM L a = 10)
W = WIDTH OF APRON (ft) [W = D o + La]
Q = FLOW (cfs)
d50 = STONE SIZE (ft) [FROM FIGURE 8-1, CHARLOTTE STORMWATER DESIGN MANUAL]
BMP #1
D 30
Q 14.46
Do 2.5
3Do 7.5
La 16
W 18.5
d50 0.75
*MIN. APRON SIZE NOT TO BE LESS THAN 8'Wx11'Lx18"D CLASS B APRON
Page 12 of 138
Page 13 of 138

FC CAROLINAS SOCCER COMPLEX

WAXHAW, NORTH CAROLINA

DROP INLET
CALCULATIONS

Page 14 of 138
DROP INLET CALCULATIONS11/29/2017Rational MethodProject: FC CAROLINAS SOCCER COMPLEXDesign Objective: PROVIDE 6" FREEBOARD AT INLET FOR DESIGN STORM (10 YR)A B A+BStructure Area Tc ( t ) Intensity ( i ) Flow Orifice Weir Depth of Water Rim El. Water El H.P. El.Acerage (Min.) (in/hr) cfs(ft) ft)over D.I. (ft)(ft) (ft.) (ft)DI-2C 1.16 0.35.007.032.450.02 0.160.16660.82 660.98 662.88 O.K.DI-2D 0.56 0.35.007.031.180.00 0.100.10659.72 659.82 662.88 O.K.DI-2E 0.53 0.35.007.031.120.00 0.100.10660.73 660.83 662.88 O.K.DI-2F 1.2 0.35.007.032.530.02 0.170.17672.26 672.43 675.28 O.K.DI-2G 0.32 0.35.007.030.670.00 0.070.07673.70 673.77 674.88 O.K.DI-2H 0.77 0.35.007.031.620.01 0.130.13672.55 672.68 674.50 O.K.DI-5A 1.09 0.35.007.032.300.02 0.160.16660.72 660.88 663.28 O.K.DI-5B 1.17 0.35.007.032.470.02 0.170.17660.53 660.70 661.50 O.K.DI-5C 0.22 0.35.007.030.460.00 0.050.05660.92 660.97 662.88 O.K.DI-5D 0.31 0.35.007.030.650.00 0.070.07660.92 660.99 662.88 O.K.DI-5E 0.55 0.35.007.031.16 0.00 0.100.10677.05 677.15 678.00 O.K.DI-6A 1.7 0.655.007.037.770.19 0.360.36665.41 665.77 667.29 O.K.Coeff.P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\STORM DRAINAGE\16240-DI.xlsPage 15 of 138
DROP INLET CALCULATIONS 11/29/2017
Project: FC Carolinas Soccer Complex
Design Objective: The flow capacity of a slab type inlet (NCDOT STD.)* with 6" (height of opening)
and 10" (height to top of slab).
(DI-3A)
Q (10) = 13.63 cfs See previous runoff calc's
Slab Type Drop Inlet for 18" RCP
Top of Slab Elevation= 674.43 6" opening w/ 4" thick slab
Opening Elevation= 673.60
General Equation for a broad-crested weir for calculating the max. flow capacity:
Q=CLH^1.5
The slab type catch basin will have four open sides therefore the flow for
A and B will be multiplied by two and summed.
Q(total)= 14.56 cfs
14.56 cfs < 28.37 cfs, therefore not O.K.
I) Calculating flow using 6" of head.
Difference in Head= 1.40
A B
C= 3.087 C= 3.087
L= 4.00 L= 2.67
H= 0.50 H= 0.50
Q= 4.37 Q= 2.91
Q(total)= 14.56
14.56cfs > 13.63 cfs, therefore O.K.
* See attachment for description and dimensions
Opening Elevation= 673.60
Top of Slab Elevation= 674.43
High Point Elevation= 675.00
Freeboard = 0.57 > 0.5 ft therefore, OK
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\STORM DRAINAGE\16240-DI.xls
Page 16 of 138
DROP INLET CALCULATIONS 11/29/2017
Project: FC CAROLINAS SOCCER COMPLEX
Design Objective: The flow capacity of a slab type inlet (NCDOT STD.)* with 6" (height of opening)
and 10" (height to top of slab).
(DI-4A)
Q (10) = 12.15 See previous runoff calc's
Slab Type Drop Inlet for 15" RCP
Top of Slab Elevation= 668.83 6" opening w/ 4" thick slab
Opening Elevation= 668.00
General Equation for a broad-crested weir for calculating the max. flow capacity:
Q=CLH^1.5
I) Calculating flow using 6" of head.
A B
C= 3.087 C= 3.087
L= 4.00 L= 2.67
H= 0.50 H= 0.50
Q= 4.37 Q= 2.91
The slab type catch basin will have four open sides therefore the flow for
A and B will be multiplied by two and summed.
Q(total)= 14.56 cfs
14.56 cfs > 12.15 cfs, therefore O.K.
Opening Elevation= 668.00
Top of Slab Elevation= 668.83
High Point Elevation= 669.20
Freeboard = 0.70 > 0.5 ft therefore, OK
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\STORM DRAINAGE\16240-DI.xls
Page 17 of 138
FC CAROLINAS SOCCER COMPLEX

WAXHAW, NORTH CAROLINA

SWALE CALCULATIONS

North American Green Erosion Control Materials Design Software was used to determine the
following:

• The normal depth of the swale under poorly maintained grass depth conditions.
• The vegetation stability when the grass is properly maintained by a homeowner.
• The temporary liner stability before the site is stabilized.

The drainage areas and swale slopes were determined from the construction drawings. The
retardance class was changed to D (grass depth 2-6 inches) for a properly maintained grass
swale to determine vegetation stability. The normal water depth was determined by using a
unreinforced vegetation matting type with a retardance class of B (grass depth 12-24 inches)
for an under or none maintained grass swale for use with the freeboard calculations. Then the
swale was changed to unvegetated with a S75 temporary liner to determine liner stability.
Swales that were unstable for any reason either were widened and/or lined with different
temporary liners. If the calculations of the temporary linear showed a velocity of less than 2
fps during a 10 year storm event then the temporary linear was removed.

“Each swale cross section was analyzed using the largest contributing flow”
Swale Drainage Structure Flow
A DI 3A  (1.67*0.40*7.03) = 4.50 cfs
B DI 3A (2.89*0.40*7.03) = 8.1 cfs
C DI 6A (1.0*0.30*7.03) = 2.10 cfs
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Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Tuesday, Nov 14 2017
RIP RAP DITCH
Trapezoidal
Bottom Width (ft) = 2.00
Side Slopes (z:1) = 3.00, 3.00
Total Depth (ft) = 1.00
Invert Elev (ft) = 1.00
Slope (%) = 1.50
N-Value = 0.037
Calculations
Compute by: Known Q
Known Q (cfs) = 4.50
Highlighted
Depth (ft) = 0.52
Q (cfs) = 4.500
Area (sqft) = 1.85
Velocity (ft/s) = 2.43
Wetted Perim (ft) = 5.29
Crit Depth, Yc (ft) = 0.44
Top Width (ft) = 5.12
EGL (ft) = 0.61
0 1 2 3 4 5 6 7 8 9 10
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
Reach (ft)
Page 28 of 138

FC CAROLINAS SOCCER COMPLEX

WAXHAW, NORTH CAROLINA

EROSION CONTROL CALCULATIONS

Narrative:

Erosion control measures have been designed in accordance with Town of Waxhaw
and North Carolina Department of Environmental Quality requirements and standards.
Erosion control is maintained on the site via silt fence, diversion ditches, storm
drainage inlet protection and riser and skimmer basins. The sediment pond and
skimmer have been sized for the 10 year storm event

Page 29 of 138
The ISAACS GROUP Date 9/16/2017
Broxton Soccer Complex Town of Waxhaw, Unin County NC
Riser Basin Design & Calculations (BASIN #1)
Peak Flow Calculation
Total Time of Concentration, Tc 18.76 (min.)
i , 10 yr. Rainfall Intensity (table 3-3)4.56 (in./hr.)
C, Rainfall Runoff Coefficient 0.45
AD, Drainage Area to Structure (Pre-Developed)761,240 (sq. ft.) 17.48 ac
Ad, Drainage Area to Structure (Post-Developed)865,220 (sq. ft.) 19.86 ac
Drainage Area to Structure 19.86 (ac.)
Area of disturbance for structure 13.87 (ac.) (INCLUDES HOMEBUILDER PHASE)
Q10, Peak Flow = Ci A 40.76 (cfs)
Bottom of Basin Elevation =639.00
Depth of Basin (to top riser)8.70 (ft.)
Riser Spillway Elevation = 647.70 Diff. b/t Riser and Emer. Spillway= 1.05
Emergency Spillway Elev. = 648.75
Top of Dam Elevation = 650.25
Contour Area Area Volume Total
Elev. (sq. ft.) (ac. ft.) (cu. ft.) (cu. ft.)
639.00 3,463 0.079
640.00 4,649 0.107 4,056 4,056
641.00 5,942 0.136 5,296 9,352
642.00 7,359 0.169 6,651 16,002
643.00 8,884 0.204 8,122 24,124
644.00 10,522 0.242 9,703 33,827
644.50 12,346 0.283 5,717 39,544
645.00 15,863 0.364 7,052 46,596
646.00 17,292 0.397 16,578 63,173
647.00 18,778 0.431 18,035 81,208
648.00 20,321 0.467 19,550 82,723
648.50 21,883 0.502 10,551 93,274
649.00 22,708 0.521 11,148 104,422
Elevation of measured Storage and Surface Area =647.70
Basin Volume Required (1800cu.ft./dist. ac) = 24,966 (cu. ft.)
Basin Volume Provided at Spillway =82,269 (cu. ft.)Greater than required, therefore OK
Required Basin Surface Area (Q10x435 sq.ft.) =17,730 (sq. ft.)
AS, Surface Area Provided =19,858 (sq. ft.)Greater than required, therefore OK
See Next page for Principal Spillway Riser Barrel Design
Volume Calculation
Page 30 of 138

Principal Spillway Riser Barrel Design:
i , 2 yr. Rainfall Intensity (table 3-3)3.04 (in./hr.)
Q2, Peak Flow = Ci A =27.17 (cfs)
Proposed Barrel Dia. =30 (in.)
Proposed Barrel Length (5.0' increments) =72.0 (ft.)
Proposed Riser width or diameter =48 (in.)
Analyze Weir, Orifice and Barrel flow for limiting (controling) flow in principal spillway
Weir flow Q=CLH^1.5 19.87 cfs
C=3.1 , H= Height b/t riser and emer. Spillway
L=total length of rectangular weir opening
Orifice flow Q=CA(2gH)^0.5 31.63 cfs
C=0.6
H=height b/t riser and emergency spillway
Pipe flow QP = (a√2gH)/√(1+Km+KpL) 58.24 cfs
Km=1
Kp=0.0341 from table 8.07a
H=depth from bottom basin to emergency spillway
Minimum principal spillway flow= 19.87 Greater than Q2, therefore OK
Emergency Spillway Calculation:
Q10=40.76 (cfs)
QP=19.87 (cfs)
20.89 (cfs)
20.0 (ft.)
h= 0.49 (ft.)OK Principal outlet carrys the 10 year storm. 19' spillway provided
Concrete Anchor Buoyancy Calculation
Riser Height (h) =11.05 (ft.)(50-year max. W.S.E.L. depth)
Riser Outside Length (l) = 5.00 (ft.)
Riser Outside Width (w) = 5.00 (ft.)
Riser Wall Thickness (t) =0.50 (ft.)
Vol. of riser (VR) =276.3 (ft3)V R = l x w x h
Wt. of H2O displaced (WR)=17238.0 (lbs)W R = 62.4 lbs/ft 3 x V R
Conc. pad thickness =24 (in.)
Conc. pad width/length =10 (ft.)
Vol. of conc. pad (VC) =200.00 (ft3)
Wt. of H2O displaced (WC) =12480 (lbs)W C = 62.4 lbs/ft 3 x V C
Tot. Wt. of H2O displaced (WD) =29718.0 (lbs)WD = WR + WC
Unit wt. of concrete = 150 (lbs/ft3)
Wt. of conc. pad = 30000 (lbs)
Riser Outside Area (Ao) = 25 (ft2)
Riser Inside Area (Ai) = 16 (ft2)
Wt. of Riser Structure = 14917.5 (lbs)
Factor of safety = wt. Conc. Pad + wt. Riser Structure
wt. of H2O displaced
F.S.= 1.51 OK
See following sheet for Skimmer Size Calculation from Fairclothskimmer.com
Qe = Q10-QP =
Spillway Width =
Page 31 of 138
The ISAACS GROUP 11/7/2017
Broxton Soccer Complex Union County, NC
Skimmer Basin Design & Calculations (BASIN #2)
Peak Flow Calculation
Total Time of Concentration, T c 5.00 (min.)
i , 10 yr. Rainfall Intensity 7.03 (in./hr.)
C, Rainfall Runoff Coefficient 0.45
AD, Drainage Area to Structure (Pre-Developed)204,481 (sq. ft.) 4.69 (ac.)
AD, Drainage Area to Structure (Post-Developed)71,071 (sq. ft.) 1.63 (ac.)
Drainage Area to Structure 4.69 (ac.) Pre-Developed
Area of disturbance for structure 2.86 (ac.)
Q10, Peak Flow = Ci A 14.850 (cfs)
Bottom of Basin Elevation =664.50
Depth of Basin (to spillway)3.50 (ft.)
Emergency Spillway Elev. = 668.00
Top of Dam Elevation = 669.50
Contour Area Area Volume Total
Elev. (sq. ft.) (ac. ft.) (cu. ft.) (cu. ft.)
664.50 535 0.012
665.00 937 0.022 368 368
666.00 2,072 0.048 1,505 1,873
667.00 3,118 0.072 2,595 4,468
668.00 4,878 0.112 3,998 8,466
669.00 6,621 0.152 9,739 14,207
669.50 7,405 0.170 9,212 17,678
Basin Volume Required (1800cu.ft./dist. ac) =5,155 (cu. ft.)
Basin Volume Provided at Spillway =8,466 (cu. ft.)Greater than required, therefore OK
Required Basin Surface Area (Q 10x325 sq.ft.) = 4,826 (sq. ft.)
AS, Surface Area Provided = 4,878 (sq. ft.)Greater than required, therefore OK

Emergency Spillway Calculation:
Emergency Spillway Calculation:Q=CLH^1.5
C= 3
Q10=14.850 (cfs)
Spillway Width =15.0 (ft.)
h= 0.48 (ft.)<0.5', Therefore OK
Volume Calculation
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\16240-EC-BASIN.xls
Page 32 of 138
The ISAACS GROUP 11/7/2017
Broxton Soccer Complex Union County, NC
Skimmer Basin Design & Calculations (BASIN #3)
Peak Flow Calculation
Total Time of Concentration, T c 5.00 (min.)
i , 10 yr. Rainfall Intensity 7.03 (in./hr.)
C, Rainfall Runoff Coefficient 0.45
AD, Drainage Area to Structure (Pre-Developed)154,775 (sq. ft.) 3.55 (ac.)
AD, Drainage Area to Structure (Post-Developed)154,775 (sq. ft.) 3.55 (ac.)
Drainage Area to Structure 3.55 (ac.) Post-Developed
Area of disturbance for structure 0.75 (ac.)
Q10, Peak Flow = Ci A 11.240 (cfs)
Bottom of Basin Elevation =682.00
Depth of Basin (to spillway)2.50 (ft.)
Emergency Spillway Elev. = 684.50
Top of Dam Elevation = 686.00
Contour Area Area Volume Total
Elev. (sq. ft.) (ac. ft.) (cu. ft.) (cu. ft.)
682.00 838 0.019
683.00 4,346 0.100 2,592 2,592
684.00 10,981 0.252 7,664 10,256
684.50 15,709 0.361 6,673 16,928
685.00 21,179 0.486 9,222 26,150
686.00 32,176 0.739 35,914 52,842
Basin Volume Required (1800cu.ft./dist. ac) =1,350 (cu. ft.)
Basin Volume Provided at Spillway =16,928 (cu. ft.)Greater than required, therefore OK
Required Basin Surface Area (Q 10x325 sq.ft.) = 3,653 (sq. ft.)
AS, Surface Area Provided = 15,709 (sq. ft.)Greater than required, therefore OK

Emergency Spillway Calculation:
Emergency Spillway Calculation:Q=CLH^1.5
C= 3
Q10=11.240 (cfs)
Spillway Width =15.0 (ft.)
h= 0.40 (ft.)<0.5', Therefore OK
Volume Calculation
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\16240-EC-BASIN.xls
Page 33 of 138
Faircloth Skimmer Sizing Calculation 
Basin No. 1 
Volume required = 24,966 cf 
Volume provided = 82,269 cf 
1. Size skimmer using a 2 day drawdown based on required volume 

2. Check Skimmer size with a 5 day drawdown per provided volume 

Use 4.0” skimmer with 3.2” orifice. 
Basin No. 2  
Volume required = 5,155cf 
Volume provided = 8,466 cf 
1. Size skimmer using a 2 day drawdown based on required volume 

2. Check Skimmer size with a 5 day drawdown per provided volume 

Use 2.0” skimmer with 1.7” orifice. 

Page 34 of 138
Basin No. 3 
Volume required = 1,350 cf 
Volume provided = 16,928 cf 
3. Size skimmer using a 2 day drawdown based on required volume 

4. Check Skimmer size with a 5 day drawdown per provided volume 

Use 1.5” skimmer with 0.9” orifice. 

Page 35 of 138
Channel Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Monday, Nov 13 2017
TEMPORARY DIVERSION DITCH
Triangular
Side Slopes (z:1) = 3.00, 3.00
Total Depth (ft) = 2.00
Invert Elev (ft) = 1.00
Slope (%) = 1.50
N-Value = 0.030
Calculations
Compute by: Known Q
Known Q (cfs) = 9.52
Highlighted
Depth (ft) = 0.95
Q (cfs) = 9.520
Area (sqft) = 2.71
Velocity (ft/s) = 3.52
Wetted Perim (ft) = 6.01
Crit Depth, Yc (ft) = 0.92
Top Width (ft) = 5.70
EGL (ft) = 1.14
0 2 4 6 8 10 12 14 16
Elev (ft)Depth (ft)Section
0.50 -0.50
1.00 0.00
1.50 0.50
2.00 1.00
2.50 1.50
3.00 2.00
3.50 2.50
4.00 3.00
Reach (ft)
Page 36 of 138

FC CAROLINAS SOCCER COMPLEX

TOWN OF WAXHAW, NORTH CAROLINA

BMP DETENTION & WATER QUALITY CALCULATIONS

NO. BY DATE REVISION
1 RER 10-16-17 PER COMMENTS
2 RER 12/04/17 PER COMMENTS
3 RER 12/21/17 PER COMMENTS

Page 37 of 138
Project Narrative

Project Description
The project site is located in Town of Waxhaw, Union County, N.C. and is an approximately 61 acre parcel along
Old Waxhaw Monroe Road (S.R. 1111). The proposed project consists of a recreation facility and driveway
connection to Old Waxhaw Monroe Road in accordance with NCDOT requirements. The project area drains to
Waxhaw Creeks and is subject to the site specific Water Quality Management requirements prescribed by the
N.C. Division of Water Quality (NCDWQ) as outlined in the regulations for the Goose Creek Watershed.

NCDWQ requirements that have been met in the design of this project include the control and treatment of the
difference in the stormwater runoff from the pre-development and post-development conditions for the one-year,
24-hour storm, with structural stormwater controls that promote infiltration of flows and groundwater recharge, if
practicable based upon soil conditions.

The rainfall amounts used in the analysis of this project were obtained from Charlotte-Mecklenburg Storm Water
Design Manual.

Structural stormwater controls have been provided to meet the following minimum requirements:

a. Remove an 85 percent average annual amount of Total Suspended Solids
b. Draw down the treatment volume no faster than 48 hours, but no slower than 120 hours, for detention
ponds.
c. Discharge the storage volume at a rate equal or less than the pre-development discharge rate for the
one-year, 24-hour storm.
d. Meet design of Stormwater Management Measures set forth in 15A NCAC 02H .1008.

Additional stormwater management measures have been provided for this project as required by Town of
Waxhaw to include the following:

a. In accordance with Section 3.1.3 of the Town of Waxhaw Stormwater Design Manual, the post
developed discharge rate at the property boundary is less than or equal to the pre development rate
for the (2 & 10) two and ten year storm events.

Natural Resources Inventory
The parcel is covered in approximately 65% woods and 35% grass fields. Soil & Forestry Services of the
Carolinas, PA (S&FS) has performed a stream/wetlands delineation/study and confirmed with the U.S. Army
Corp of Engineers and N.C. Division of Water Quality that an existing on-site wetland and two streams which
intersect the property are considered Waters of the State (Reference Wetland JD Dated 3/12/15 per attached in
appendix A)

Existing on-site slopes range from 2 to 20 percent on average and existing soil types on site is predominantly
Georgeville Silty Clay Loam (Hydrologic Group B). Soil & Forestry Services of the Carolinas, PA (S&FS) has
performed on-site geotechnical testing to establish soil suitability for proposed stormwater BMP construction, as
well as establish hydraulic conductivity of on-site soils for suitability for infiltration devices along with the vertical
location of Seasonal High Water Tables at the locations of the proposed BMP 1.

Existing and Proposed Drainage Patterns
Proposed drainage patterns to the proposed on-site BMP maintain existing drainage patterns to the maximum
extent practicable as need to create a balanced distribution of storm water flow thru BMP 1 in a consistent
manner with existing flows.

Page 38 of 138
Proposed BMP #1 (Wet Pond)
BMP #1 (Wet Pond) has been designed per the NCDENR requirements of the contributing drainage area
(18.81 ac.) to meet 85% TSS removal, 25% TN and 40% TP removal targets. The hydraulic conductivity of the
existing soils at the location of BMP #1 are 0.17 cm/hr (0.0688 in/hr) and do not support infiltration measures.
Additionally, the SHWT was established as required to establish the minimum vertical separations as outlined by
the NCDENR and DWQ requirements. BMP #1 meets or exceeds the following requirements:

• The control and treatment of the difference in the stormwater runoff from the pre-development and post-
development conditions for the one-year, 24-hour storm.
• Removal of an 85 percent average annual amount of Total Suspended Solids (85% TSS removal), 25%
TN (min) and 40% TP (min) removals
• Draw down the treatment volume no faster than 48 hours, but no slower than 120 hours.
• Discharge the storage volume at a rate equal or less than the pre-development
discharge rate for the one-year, 24-hour storm
• Meet design of Stormwater Management Measures set forth in 15A NCAC 02H .1008.
• The post developed discharge rate at the property boundary is less than or equal to the pre development
rate for the (2 & 10) two and ten year storm events.

Page 39 of 138
BMP MASTER SUMMARY
BMP #1 (WETPOND)
Storm Event 1 Yr.-24 hr.2 Yr.-6 hr.10 Yr. - 6 hr.100 Yr. - 6 hr.
(BMP #1-Wetpond)
Pre-Dev. Flow 0.83 0.95 8.58 23.47
Post-Dev Flow 18.97 22.21 59.43 109.45
Routed Flow 0.33 0.34 5.25 48.69
Water Surface El.646.58 646.52 648.57 649.25
Freeboard Depth 3.67 3.73 1.68 1.00
DETENTION ANALYSIS SUMMARY
ANALYSIS POINT 1
Storm Event 1 Yr.-24 hr.2 Yr.-6 hr.10 Yr. - 6 hr.100 Yr. - 6 hr.
Pre-Dev. Flow 0.06 0.08 1.64 5.49
Post-Dev Flow 0.04 0.06 0.94 3.00
ANALYSIS POINT 2
Storm Event 1 Yr.-24 hr.2 Yr.-6 hr.10 Yr. - 6 hr.100 Yr. - 6 hr.
Pre-Dev. Flow 0.83 0.95 8.58 23.47
Post-Dev Flow 0.34 0.34 5.25 48.69
ANALYSIS POINT 3
Storm Event 1 Yr.-24 hr.2 Yr.-6 hr.10 Yr. - 6 hr.100 Yr. - 6 hr.
Pre-Dev. Flow 0.96 1.13 9.94 27.01
Post-Dev Flow 0.90 1.05 9.43 25.68
Page 40 of 138
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\BMP\REVISION\16240-BMP 1 Wetpond-REV2.xls
BMP CALCULATIONS
FC CAROLINAS SOCCER COMPLEX
PROPOSED BMP #1 (WETPOND)
Wet Pond & EFS/LS Designed per NCDENR (Div. of Water Quality) and Town of Waxhaw Regulations
See Sheet C2.3 & C2.4 for Pre and Post-develop drainage area maps, Soil types, Tc flow path,
CN data and overall projet narrative.
Project Narrative:
Pond Drainage Information:
Proposed BMP No.:1 (Wet Pond)
Project Site Area (Ac.)23.13
Proposed Drainage Area (Ac.) =18.81 See Drainage Area Exhibit
Existing Impervious Area (BUA) (Ac.) =0.22
Proposed Impervious Area (BUA) (Ac.) =7.25
Percent Impervious Area =38.54 (Impervious Area divided by Drainage Area) x 100
Reference Post-Developed section of this report for Curve Numbers, Time of Concetration values, and Post-Developed Flows
for 1, 2, 10 and 100 year storm events to BMP #1.
Page 41 of 138
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Calculations\BMP\REVISION\16240-BMP 1 Wetpond-REV2.xls
Pond Stage-Storage Information:
Perm. Water surface elevation =644.5
Elevation
Total Surface Area
Including Forebays
(s.f.)
Cummulative Det'n
Volume (cu.ft.)
Cummulative
Wet Volume
Including
Forebays
(cu.ft.)
Forebay
Surface Area
(s.f.)
Forebay
Cumulative
Volume (cu.
ft.)
Percentage of
total Volume
(20% desired)
639 3501 0 0 0 0
640 4683 0 4,092 744 372
641 5978 0 9,423 1130 1,309
642 7387 0 16,105 1573 2,661
643 8908 0 24,253 2072 4,483
644 10542 0 33,978 2628 6,833
644.5 12284 0 39,684 2909 8,217 20.71
645 15708 6,998 46,682 0 0
646 17126 23,415 63,099 0 0
647 18600 41,278 80,962 0 0
648 20130 60,643 100,327 0 0
649 22504 81,960 121,644 0 0
650.2 25540 110,786 150,470 0 0
Permanent Pool Calculations:
Permanent Pool Elevation =644.5 See Plan
Permanent Pool Average Depth =3.19
1.41
11,555 =((SA/DA)/100) (Ac.)(43560)
Surface Area Provided (s.f.) @ 644.50 12,284 OK
Temporary Water Quality Storage Calculations:
(Simple Method)
Where: Rv=Runoff coefficient, IA=Impervious fraction (Imp. DA/Total DA), V=Volume,
1-yr, 24-hr RD=Design rainfall 2.78 (in), A=Watershed Area
Pre-Development: Rv=0.05+(0.9 x IA)0.061 (ac-ft)
Post-Development: Rv=0.05+(0.9 x IA)0.397 (ac-ft)
V=3,630 x RD x (Rv Post-Rv Pre) x A 63,848 (cu. ft)
Required Water Quality Volume, WQv (ft3)63,848 (cu. ft)
Water Quality Storage Provided @ elev.:648.13
Temporary Water Quality De-watering Time Summary:
See orifice calculations below for dewatering time of WQv
Orifice Equation:Q=CA(2gH)1/2
Orifice coefficient, C 0.600
Average head, H 1.750 ft
48-hr release rate, Q 0.306 cfs
Orifice area, A 0.048 sf
Minimum orifice diameter, D 3.0 in
120-hr release rate, Q 0.122 cfs
Orifice area, A 0.019 sf
Maximum orifice diameter, D 1.9 in
Using a 3" orifice, the time to drain the water at peak elevation of 648.13 is greater than / equal to min. 48 hours.
Per NCDENR average
depth equation Option 3
Interpolated from Storage Table
SA/DA ratio for 85% Pollutant Removal Efficiency =
Required Surface Area of Wet Pond (s.f.) =
Interpolated From Table 1 in NCDEQ Stormwater
Design Manual
Page 42 of 138
CONCRETE ANCHOR ANTI-FLOTATION CALCULATION:
BMP #1 (WET POND)
Height of riser =10.0 ft
Cross Sectional Area of Riser =25.0 sf 4'x4' box w/ 6" wall thickness = 5'x5' box
Vol. of riser =250 cf
Wt. of H2O displaced =15,600 lbs
Conc. pad thickness =24 in
Conc. pad width/length =10 ft
Vol. of conc. pad =200 cf
Wt. of H2O displaced =12,480 lbs
Total Wt. of H 2O displaced =28,080
Unit wt. of concrete (pcf) = 150
Wt. of conc. pad (lb.) = 30,000
Vol. of conc. box (cf.) = 94 ((25-16)*(10)+(0.5*4*4))-((1.9*3.5)+(3.1416*1.25*1.25)/4)*0.5
Wt. of conc. box (lb.) = 14,109
Total Wt. of conc. (lb.) = 44,109
Factor of safety = wt. Conc. Pad + Conc. Box
wt. Of H2O displaced
F.S.= 1.57
Page 43 of 138
Existing and Proposed Drainage Patterns & Points of Analysis

Drainage patterns to the proposed on-site BMP maintain existing drainage patterns to the maximum extent
practicable as needed to create a balanced distribution of storm water flow thru BMP 1 in a consistent
manner with existing flows. Special consideration was given to the proposed locations of BMP outfalls to
minimize off-site impacts during various storm events due to existing off-site infrastructure limitations.

As seen on the attached Pre-Developed Drainage Area map (Sheet C2.3) and Post-Developed Drainage
Area Map (Sheet C2.4), three points of analysis was selected, Analysis Point 1, 2 & 3 for evaluation of Pre
and Post Developed stormwater flows resulting from the development of the FC Carolinas recreation
facility. Drainage area limits shown are not intended to represent the total drainage area to each point of
analysis, but to evaluate the net increase or decrease in stormwater flows for the 1, 2, 10, and 100 year
storm events for the contributing areas which encompass the entire area to be developed. As seen below
in the Results Summary, there is no net increase in stormwater flow for all storm events up to and including
the 10-year storm for the points of analysis evaluated and larger storm events exceeding 10-year event are
being conveyed thru stable channels without negative impacts to downstream properties.

Hydrologic Precipitation Data used in the detention and water quality analysis for the 1, 2, 10, and 100 year
storm events was taken from the City of Charlotte Stormwater Services Dept. published data per the
attached documents on the following pages. The project site is within a few miles of the City of Charlotte
limits and the rainfall depths used accurately approximate average rainfall amounts per the NOAA National
Weather Service Hydrometeorological Design Studies Center.

Future Development to Proposed BMP #1 (Wetpond)

The proposed BMP #1 (Wetpond) was designed and sized to accommodate future development as
seen on the attached Post-Developed Drainage Area Map (Sheet C2.4). Storm runoff from the future
development shall be connected to the proposed storm drainage system and shall be detained and
routed to ensure that post-developed flows at point of analysis will not exceed the pre-developed flows.

Page 44 of 138
A-PRE OUT PT.-1
B-POST OUT PT.-1
A-PRE DEV 3
PRE-A3
B-POST DEV 4
POST-A4
Page 45 of 138
Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 3..... Tc Calcs ........................... 2.01

B-POST DEV 4.... Tc Calcs ........................... 2.03
********************** CN CALCULATIONS *********************

A-PRE DEV 3..... Runoff CN-Area ..................... 3.01

B-POST DEV 4.... Runoff CN-Area ..................... 3.02

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 46 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ Meck Co NC 24

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
1 2.5800 Synthetic Curve DETENT SCS TP II-6 MIN

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-
ft
----------------- ---- ------ ---------- -- --------- -------- -------- --------
----
A-PRE DEV 3 AREA 1 .030 12.5000 .06

*A-PRE OUT PT.-1 JCT 1 .030 12.5000 .06

B-POST DEV 4 AREA 1 .017 12.3500 .04

*B-POST OUT PT.-1 JCT 1 .017 12.3500 .04

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 47 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Shallow
Hydraulic Length 513.00 ft
Slope .051700 ft/ft
Unpaved
Avg.Velocity 3.67 ft/sec
Segment #1 Time: .0388 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .053300 ft/ft
Avg.Velocity .19 ft/sec
Segment #2 Time: .2251 hrs
------------------------------------------------------------------------
=========================
Total Tc: .2639 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 48 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 49 of 138
Type.... Tc Calcs Page 2.03
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Shallow
Hydraulic Length 446.00 ft
Slope .050400 ft/ft
Unpaved
Avg.Velocity 3.62 ft/sec
Segment #1 Time: .0342 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 100.00 ft
2yr, 24hr P 3.1200 in
Slope .040000 ft/ft
Avg.Velocity .15 ft/sec
Segment #2 Time: .1825 hrs
------------------------------------------------------------------------
=========================
Total Tc: .2167 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 50 of 138
Type.... Tc Calcs Page 2.04
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 51 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .070 61.00
Woods, Class B Soil, Good 55 3.670 55.00
COMPOSITE AREA & WEIGHTED CN ---> 3.740 55.11 (55)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 52 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .340 61.00
Wooded, Class B Soil, Good 55 1.430 55.00
COMPOSITE AREA & WEIGHTED CN ---> 1.770 56.15 (56)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 53 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 3... 2.01, 3.01

----- B -----
B-POST DEV 4... 2.03, 3.02

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:41:12 Date: 12/21/2017
Page 54 of 138
Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 3..... Tc Calcs ........................... 2.01

B-POST DEV 4.... Tc Calcs ........................... 2.03
********************** CN CALCULATIONS *********************

A-PRE DEV 3..... Runoff CN-Area ..................... 3.01

B-POST DEV 4.... Runoff CN-Area ..................... 3.02

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 55 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ 6 Hour Storms

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
100 5.3400 Time-Depth Curve DETENT 100 Year 6 Hour
.10 3.7220 Time-Depth Curve DETENT 10 Year 6 Hour
..2 2.2800 Time-Depth Curve DETENT 2 Year 6 Hour

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-
ft
----------------- ---- ------ ---------- -- --------- -------- -------- --------
----
A-PRE DEV 3 AREA 100 .360 3.2500 5.49
A-PRE DEV 3 AREA 10 .132 3.3000 1.64
A-PRE DEV 3 AREA 2 .015 3.6500 .08

*A-PRE OUT PT.-1 JCT 100 .360 3.2500 5.49
*A-PRE OUT PT.-1 JCT 10 .132 3.3000 1.64
*A-PRE OUT PT.-1 JCT 2 .015 3.6500 .08

B-POST DEV 4 AREA 100 .180 3.2000 3.00
B-POST DEV 4 AREA 10 .068 3.2500 .94
B-POST DEV 4 AREA 2 .009 3.5500 .06

*B-POST OUT PT.-1 JCT 100 .180 3.2000 3.00
*B-POST OUT PT.-1 JCT 10 .068 3.2500 .94
*B-POST OUT PT.-1 JCT 2 .009 3.5500 .06

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 56 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Shallow
Hydraulic Length 513.00 ft
Slope .051700 ft/ft
Unpaved
Avg.Velocity 3.67 ft/sec
Segment #1 Time: .0388 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .053300 ft/ft
Avg.Velocity .19 ft/sec
Segment #2 Time: .2251 hrs
------------------------------------------------------------------------
=========================
Total Tc: .2639 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 57 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 58 of 138
Type.... Tc Calcs Page 2.03
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Shallow
Hydraulic Length 446.00 ft
Slope .050400 ft/ft
Unpaved
Avg.Velocity 3.62 ft/sec
Segment #1 Time: .0342 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 100.00 ft
2yr, 24hr P 3.1200 in
Slope .040000 ft/ft
Avg.Velocity .15 ft/sec
Segment #2 Time: .1825 hrs
------------------------------------------------------------------------
=========================
Total Tc: .2167 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 59 of 138
Type.... Tc Calcs Page 2.04
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 60 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .070 61.00
Woods, Class B Soil, Good 55 3.670 55.00
COMPOSITE AREA & WEIGHTED CN ---> 3.740 55.11 (55)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 61 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 4

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 1.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .340 61.00
Wooded, Class B Soil, Good 55 1.430 55.00
COMPOSITE AREA & WEIGHTED CN ---> 1.770 56.15 (56)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 62 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 3... 2.01, 3.01

----- B -----
B-POST DEV 4... 2.03, 3.02

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 10:32:31 Date: 12/21/2017
Page 63 of 138
A-PRE DEV 1
A-PRE OUT PT.-2
PRE-A1
B-POST DEV 1
BMP 1
POST-A1
B-POST DEV 2
B-POST OUT PT.-2
POST-A2
BMP 1
Page 64 of 138

Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 1..... Tc Calcs ........................... 2.01
********************** CN CALCULATIONS *********************

A-PRE DEV 1..... Runoff CN-Area ..................... 3.01

B-POST DEV 1.... Runoff CN-Area ..................... 3.02

B-POST DEV 2.... Runoff CN-Area ..................... 3.03
************************ TIME VS.VOL ***********************

BMP 1 OUT 1
Time vs. Volume .................... 4.01
*********************** POND VOLUMES ***********************

BMP 1........... Vol: Elev-Volume ................... 5.01
******************** OUTLET STRUCTURES *********************

BMP 1........... Outlet Input Data .................. 6.01

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 65 of 138
Table of Contents ii
Table of Contents (continued)
Individual Outlet Curves ........... 6.04
Composite Rating Curve ............. 6.08
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 66 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ Meck Co NC 24

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
1 2.5800 Synthetic Curve DETENT SCS TP II-6 MIN

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-ft
----------------- ---- ------ ---------- -- --------- -------- -------- -----------
-
A-PRE DEV 1 AREA 1 .224 12.3000 .83

*A-PRE OUT PT.-2 JCT 1 .224 12.3000 .83

B-POST DEV 1 AREA 1 1.093 11.9500 18.97

B-POST DEV 2 AREA 1 .012 12.0500 .06

*B-POST OUT PT.-2 JCT 1 1.102 20.9000 .34

BMP 1 IN POND 1 1.093 11.9500 18.97

BMP 1 OUT POND 1 1.090 21.6000 .33 646.58 .776

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 67 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .048400 ft/ft
Mannings n .0350
Hydraulic Length 300.00 ft
Avg.Velocity 13.23 ft/sec
Segment #1 Time: .0063 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 1049.00 ft
Slope .048400 ft/ft
Unpaved
Avg.Velocity 3.55 ft/sec
Segment #2 Time: .0821 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .020000 ft/ft
Avg.Velocity .13 ft/sec
Segment #3 Time: .3332 hrs
------------------------------------------------------------------------
=========================
Total Tc: .4215 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 68 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 69 of 138
Type.... Tc Calcs Page 2.03
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 70 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil. Good 61 9.810 61.00
Woods, Class B Soil, Good 55 5.490 55.00
Impervious 98 .020 98.00
Gravel 98 .140 98.00
COMPOSITE AREA & WEIGHTED CN ---> 15.460 59.25 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 71 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Off-Site Impervious 98 .081 98.00
Off-Site Gravel, Class B Soil 98 .139 98.00
Impervious 98 1.725 98.00
Open Space, Class B Soil, Good 61 10.530 61.00
Wooded, Class B Soil, Good 55 .810 55.00
Future Gravel 98 .780 98.00
Future Impervious 98 2.070 98.00
Gravel BMP Access Road 98 .154 98.00
Synthetic Turf 98 2.239 98.00
Wetpond 98 .282 98.00
COMPOSITE AREA & WEIGHTED CN ---> 18.810 75.44 (75)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 72 of 138
Type.... Runoff CN-Area Page 3.03
Name.... B-POST DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .310 61.00
Woods, Class B Soil, Good 55 .760 55.00
COMPOSITE AREA & WEIGHTED CN ---> 1.070 56.74 (57)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 73 of 138
Type.... Time vs. Volume Page 4.01
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
11.3000 | .000 .000 .000 .000 .001
11.5500 | .002 .004 .007 .014 .026
11.8000 | .045 .079 .136 .210 .286
12.0500 | .350 .390 .410 .426 .440
12.3000 | .453 .464 .475 .485 .494
12.5500 | .502 .509 .516 .522 .529
12.8000 | .534 .540 .546 .552 .558
13.0500 | .563 .568 .573 .578 .582
13.3000 | .586 .591 .595 .599 .603
13.5500 | .606 .610 .613 .617 .620
13.8000 | .623 .626 .629 .632 .635
14.0500 | .637 .640 .643 .645 .648
14.3000 | .650 .653 .655 .657 .660
14.5500 | .662 .664 .666 .669 .671
14.8000 | .673 .675 .677 .679 .681
15.0500 | .683 .685 .687 .689 .691
15.3000 | .693 .694 .696 .698 .699
15.5500 | .701 .702 .704 .706 .707
15.8000 | .709 .710 .711 .713 .714
16.0500 | .715 .716 .718 .719 .720
16.3000 | .721 .722 .723 .724 .726
16.5500 | .727 .728 .729 .730 .731
16.8000 | .732 .733 .734 .735 .736
17.0500 | .737 .738 .739 .740 .741
17.3000 | .742 .743 .743 .744 .745
17.5500 | .746 .747 .748 .749 .749
17.8000 | .750 .751 .752 .752 .753
18.0500 | .754 .755 .755 .756 .756
18.3000 | .757 .758 .758 .759 .760
18.5500 | .760 .761 .761 .762 .762
18.8000 | .763 .763 .764 .764 .765
19.0500 | .765 .766 .766 .767 .767
19.3000 | .767 .768 .768 .768 .769
19.5500 | .769 .769 .770 .770 .770
19.8000 | .770 .770 .771 .771 .771
20.0500 | .771 .771 .772 .772 .772
20.3000 | .772 .772 .772 .772 .773
20.5500 | .773 .773 .773 .773 .773
20.8000 | .773 .773 .774 .774 .774
21.0500 | .774 .774 .774 .774 .774
21.3000 | .774 .775 .775 .775 .775
21.5500 | .775 .775 .775 .775 .775
21.8000 | .775 .775 .775 .775 .776
22.0500 | .776 .776 .776 .776 .776
22.3000 | .776 .776 .776 .776 .776
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 74 of 138
Type.... Time vs. Volume Page 4.02
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
22.5500 | .776 .776 .776 .776 .776
22.8000 | .776 .776 .776 .776 .776
23.0500 | .776 .776 .776 .776 .776
23.3000 | .776 .776 .776 .776 .776
23.5500 | .776 .776 .776 .776 .776
23.8000 | .776 .776 .776 .776 .776
24.0500 | .776 .775 .774 .772 .771
24.3000 | .770 .768 .767 .766 .764
24.5500 | .763 .762 .760 .759 .757
24.8000 | .756 .755 .753 .752 .751
25.0500 | .749 .748 .747 .745 .744
25.3000 | .743 .741 .740 .739 .737
25.5500 | .736 .735 .733 .732 .731
25.8000 | .729 .728 .727 .725 .724
26.0500 | .723 .721 .720 .719 .718
26.3000 | .716 .715 .714 .712 .711
26.5500 | .710 .708 .707 .706 .704
26.8000 | .703 .702 .701 .699 .698
27.0500 | .697 .695 .694 .693 .691
27.3000 | .690 .689 .688 .686 .685
27.5500 | .684 .682 .681 .680 .679
27.8000 | .677 .676 .675 .674 .672
28.0500 | .671 .670 .668 .667 .666
28.3000 | .665 .663 .662 .661 .660
28.5500 | .658 .657 .656 .655 .653
28.8000 | .652 .651 .649 .648 .647
29.0500 | .646 .644 .643 .642 .641
29.3000 | .640 .638 .637 .636 .635
29.5500 | .633 .632 .631 .630 .628
29.8000 | .627 .626 .625 .623 .622
30.0500 | .621 .620 .619 .617 .616
30.3000 | .615 .614 .612 .611 .610
30.5500 | .609 .608 .606 .605 .604
30.8000 | .603 .602 .600 .599 .598
31.0500 | .597 .596 .594 .593 .592
31.3000 | .591 .590 .588 .587 .586
31.5500 | .585 .584 .582 .581 .580
31.8000 | .579 .578 .576 .575 .574
32.0500 | .573 .571 .570 .569 .568
32.3000 | .566 .565 .564 .563 .562
32.5500 | .560 .559 .558 .557 .556
32.8000 | .554 .553 .552 .551 .549
33.0500 | .548 .547 .546 .545 .543
33.3000 | .542 .541 .540 .539 .538
33.5500 | .536 .535 .534 .533 .532
33.8000 | .531 .530 .529 .528 .527
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 75 of 138
Type.... Time vs. Volume Page 4.03
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
34.0500 | .526 .524 .523 .522 .521
34.3000 | .520 .519 .518 .517 .516
34.5500 | .515 .514 .513 .512 .511
34.8000 | .509 .508 .507 .506 .505
35.0500 | .504 .503 .502 .501 .500
35.3000 | .499 .498 .497 .496 .494
35.5500 | .493 .492 .491 .490 .489
35.8000 | .488 .487 .486 .485 .484
36.0500 | .482 .481 .480 .479 .478
36.3000 | .477 .476 .475 .474 .473
36.5500 | .472 .471 .470 .468 .467
36.8000 | .466 .465 .464 .463 .462
37.0500 | .461 .460 .459 .458 .457
37.3000 | .456 .455 .454 .453 .452
37.5500 | .451 .450 .448 .447 .446
37.8000 | .445 .444 .443 .442 .441
38.0500 | .440 .439 .438 .437 .436
38.3000 | .435 .434 .433 .432 .431
38.5500 | .430 .429 .428 .427 .426
38.8000 | .425 .424 .423 .422 .421
39.0500 | .420 .419 .418 .417 .416
39.3000 | .415 .414 .413 .412 .411
39.5500 | .410 .409 .408 .407 .406
39.8000 | .405 .404 .403 .402 .401
40.0500 | .400 .399 .398 .397 .396
40.3000 | .395 .394 .393 .392 .391
40.5500 | .390 .389 .388 .387 .386
40.8000 | .385 .384 .384 .383 .382
41.0500 | .381 .380 .379 .378 .377
41.3000 | .376 .375 .374 .373 .372
41.5500 | .371 .370 .369 .368 .367
41.8000 | .366 .366 .365 .364 .363
42.0500 | .362 .361 .360 .359 .358
42.3000 | .357 .356 .355 .354 .353
42.5500 | .353 .352 .351 .350 .349
42.8000 | .348 .347 .346 .345 .344
43.0500 | .343 .343 .342 .341 .340
43.3000 | .339 .338 .337 .336 .335
43.5500 | .334 .334 .333 .332 .331
43.8000 | .330 .329 .328 .327 .327
44.0500 | .326 .325 .324 .323 .322
44.3000 | .321 .320 .320 .319 .318
44.5500 | .317 .316 .315 .314 .313
44.8000 | .313 .312 .311 .310 .309
45.0500 | .308 .307 .307 .306 .305
45.3000 | .304 .303 .302 .302 .301
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 76 of 138
Type.... Time vs. Volume Page 4.04
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
45.5500 | .300 .299 .298 .297 .296
45.8000 | .296 .295 .294 .293 .292
46.0500 | .292 .291 .290 .289 .288
46.3000 | .287 .287 .286 .285 .284
46.5500 | .283 .282 .282 .281 .280
46.8000 | .279 .278 .278 .277 .276
47.0500 | .275 .274 .274 .273 .272
47.3000 | .271 .270 .270 .269 .268
47.5500 | .267 .266 .266 .265 .264
47.8000 | .263 .262 .262 .261 .260
48.0500 | .259 .259 .258 .257 .256
48.3000 | .256 .255 .254 .253 .252
48.5500 | .252 .251 .250 .249 .249
48.8000 | .248 .247 .246 .246 .245
49.0500 | .244 .243 .243 .242 .241
49.3000 | .240 .240 .239 .238 .237
49.5500 | .237 .236 .235 .234 .234
49.8000 | .233 .232 .232 .231 .230
50.0500 | .229 .229 .228 .227 .226
50.3000 | .226 .225 .224 .224 .223
50.5500 | .222 .221 .221 .220 .219
50.8000 | .219 .218 .217 .216 .216
51.0500 | .215 .214 .214 .213 .212
51.3000 | .212 .211 .210 .209 .209
51.5500 | .208 .207 .207 .206 .205
51.8000 | .205 .204 .203 .203 .202
52.0500 | .201 .201 .200 .199 .199
52.3000 | .198 .197 .196 .196 .195
52.5500 | .194 .194 .193 .192 .191
52.8000 | .191 .190 .189 .189 .188
53.0500 | .187 .186 .186 .185 .184
53.3000 | .184 .183 .182 .182 .181
53.5500 | .180 .180 .179 .178 .178
53.8000 | .177 .176 .176 .175 .174
54.0500 | .174 .173 .172 .172 .171
54.3000 | .170 .170 .169 .168 .168
54.5500 | .167 .166 .166 .165 .164
54.8000 | .164 .163 .162 .162 .161
55.0500 | .161 .160 .159 .159 .158
55.3000 | .158 .157 .157 .156 .156
55.5500 | .155 .155 .154 .154 .153
55.8000 | .152 .152 .151 .151 .150
56.0500 | .150 .149 .149 .148 .148
56.3000 | .147 .147 .146 .146 .145
56.5500 | .145 .144 .144 .143 .143
56.8000 | .142 .142 .141 .141 .140
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 77 of 138
Type.... Time vs. Volume Page 4.05
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
57.0500 | .140 .139 .139 .138 .138
57.3000 | .137 .137 .136 .136 .135
57.5500 | .135 .134 .134 .133 .133
57.8000 | .132 .132 .131 .131 .130
58.0500 | .130 .129 .129 .129 .128
58.3000 | .128 .127 .127 .126 .126
58.5500 | .125 .125 .124 .124 .123
58.8000 | .123 .122 .122 .121 .121
59.0500 | .120 .120 .119 .119 .118
59.3000 | .118 .117 .117 .116 .116
59.5500 | .116 .115 .115 .114 .114
59.8000 | .113 .113 .112 .112 .112
60.0500 | .111 .111 .110 .110 .109
60.3000 | .109 .109 .108 .108 .107
60.5500 | .107 .106 .106 .106 .105
60.8000 | .105 .104 .104 .104 .103
61.0500 | .103 .102 .102 .102 .101
61.3000 | .101 .100 .100 .100 .099
61.5500 | .099 .098 .098 .098 .097
61.8000 | .097 .097 .096 .096 .096
62.0500 | .095 .095 .094 .094 .094
62.3000 | .093 .093 .093 .092 .092
62.5500 | .092 .091 .091 .091 .090
62.8000 | .090 .090 .089 .089 .088
63.0500 | .088 .088 .088 .087 .087
63.3000 | .087 .086 .086 .086 .085
63.5500 | .085 .085 .084 .084 .084
63.8000 | .083 .083 .083 .082 .082
64.0500 | .082 .081 .081 .081 .081
64.3000 | .080 .080 .080 .079 .079
64.5500 | .079 .078 .078 .078 .078
64.8000 | .077 .077 .077 .076 .076
65.0500 | .076 .076 .075 .075 .075
65.3000 | .075 .074 .074 .074 .073
65.5500 | .073 .073 .073 .072 .072
65.8000 | .072 .072 .071 .071 .071
66.0500 | .071 .070 .070 .070 .070
66.3000 | .069 .069 .069 .069 .068
66.5500 | .068 .068 .068 .067 .067
66.8000 | .067 .067 .066 .066 .066
67.0500 | .066 .065 .065 .065 .065
67.3000 | .064 .064 .064 .064 .064
67.5500 | .063 .063 .063 .063 .062
67.8000 | .062 .062 .062 .062 .061
68.0500 | .061 .061 .061 .060 .060
68.3000 | .060 .060 .060 .059 .059
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 78 of 138
Type.... Time vs. Volume Page 4.06
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
68.5500 | .059 .059 .059 .058 .058
68.8000 | .058 .058 .058 .057 .057
69.0500 | .057 .057 .057 .056 .056
69.3000 | .056 .056 .056 .055 .055
69.5500 | .055 .055 .055 .054 .054
69.8000 | .054 .054 .054 .053 .053
70.0500 | .053 .053 .053 .052 .052
70.3000 | .052 .052 .052 .052 .051
70.5500 | .051 .051 .051 .051 .050
70.8000 | .050 .050 .050 .050 .050
71.0500 | .049 .049 .049 .049 .049
71.3000 | .049 .048 .048 .048 .048
71.5500 | .048 .047 .047 .047 .047
71.8000 | .047 .047 .046 .046 .046
72.0500 | .046 .046 .046 .045 .045
72.3000 | .045 .045 .045 .045 .045
72.5500 | .044 .044 .044 .044 .044
72.8000 | .044 .043 .043 .043 .043
73.0500 | .043 .043 .043 .042 .042
73.3000 | .042 .042 .042 .042 .041
73.5500 | .041 .041 .041 .041 .041
73.8000 | .041 .040 .040 .040 .040
74.0500 | .040 .040 .040 .039 .039
74.3000 | .039 .039 .039 .039 .039
74.5500 | .038 .038 .038 .038 .038
74.8000 | .038 .038 .038 .037 .037
75.0500 | .037 .037 .037 .037 .037
75.3000 | .036 .036 .036 .036 .036
75.5500 | .036 .036 .036 .035 .035
75.8000 | .035 .035 .035 .035 .035
76.0500 | .035 .034 .034 .034 .034
76.3000 | .034 .034 .034 .034 .033
76.5500 | .033 .033 .033 .033 .033
76.8000 | .033 .033 .033 .032 .032
77.0500 | .032 .032 .032 .032 .032
77.3000 | .032 .032 .031 .031 .031
77.5500 | .031 .031 .031 .031 .031
77.8000 | .031 .030 .030 .030 .030
78.0500 | .030 .030 .030 .030 .030
78.3000 | .029 .029 .029 .029 .029
78.5500 | .029 .029 .029 .029 .029
78.8000 | .028 .028 .028 .028 .028
79.0500 | .028 .028 .028 .028 .028
79.3000 | .027 .027 .027 .027 .027
79.5500 | .027 .027 .027 .027 .027
79.8000 | .026 .026 .026 .026 .026
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 79 of 138
Type.... Time vs. Volume Page 4.07
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
80.0500 | .026 .026 .026 .026 .026
80.3000 | .026 .025 .025 .025 .025
80.5500 | .025 .025 .025 .025 .025
80.8000 | .025 .025 .024 .024 .024
81.0500 | .024 .024 .024 .024 .024
81.3000 | .024 .024 .024 .024 .023
81.5500 | .023 .023 .023 .023 .023
81.8000 | .023 .023 .023 .023 .023
82.0500 | .023 .022 .022 .022 .022
82.3000 | .022 .022 .022 .022 .022
82.5500 | .022 .022 .022 .022 .021
82.8000 | .021 .021 .021 .021 .021
83.0500 | .021 .021 .021 .021 .021
83.3000 | .021 .021 .020 .020 .020
83.5500 | .020 .020 .020 .020 .020
83.8000 | .020 .020 .020 .020 .020
84.0500 | .020 .019 .019 .019 .019
84.3000 | .019 .019 .019 .019 .019
84.5500 | .019 .019 .019 .019 .019
84.8000 | .019 .018 .018 .018 .018
85.0500 | .018 .018 .018 .018 .018
85.3000 | .018 .018 .018 .018 .018
85.5500 | .018 .018 .017 .017 .017
85.8000 | .017 .017 .017 .017 .017
86.0500 | .017 .017 .017 .017 .017
86.3000 | .017 .017 .017 .016 .016
86.5500 | .016 .016 .016 .016 .016
86.8000 | .016 .016 .016 .016 .016
87.0500 | .016 .016 .016 .016 .016
87.3000 | .016 .015 .015 .015 .015
87.5500 | .015 .015 .015 .015 .015
87.8000 | .015 .015 .015 .015 .015
88.0500 | .015 .015 .015 .015 .014
88.3000 | .014 .014 .014 .014 .014
88.5500 | .014 .014 .014 .014 .014
88.8000 | .014 .014 .014 .014 .014
89.0500 | .014 .014 .014 .014 .014
89.3000 | .013 .013 .013 .013 .013
89.5500 | .013 .013 .013 .013 .013
89.8000 | .013 .013 .013 .013 .013
90.0500 | .013 .013 .013 .013 .013
90.3000 | .013 .012 .012 .012 .012
90.5500 | .012 .012 .012 .012 .012
90.8000 | .012 .012 .012 .012 .012
91.0500 | .012 .012 .012 .012 .012
91.3000 | .012 .012 .012 .012 .012
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 80 of 138
Type.... Time vs. Volume Page 4.08
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
91.5500 | .011 .011 .011 .011 .011
91.8000 | .011 .011 .011 .011 .011
92.0500 | .011 .011 .011 .011 .011
92.3000 | .011 .011 .011 .011 .011
92.5500 | .011 .011 .011 .011 .011
92.8000 | .010 .010 .010 .010 .010
93.0500 | .010 .010 .010 .010 .010
93.3000 | .010 .010 .010 .010 .010
93.5500 | .010 .010 .010 .010 .010
93.8000 | .010 .010 .010 .010 .010
94.0500 | .010 .010 .010 .009 .009
94.3000 | .009 .009 .009 .009 .009
94.5500 | .009 .009 .009 .009 .009
94.8000 | .009 .009 .009 .009 .009
95.0500 | .009 .009 .009 .009 .009
95.3000 | .009 .009 .009 .009 .009
95.5500 | .009 .009 .009 .009 .009
95.8000 | .008 .008 .008 .008 .008
96.0500 | .008 .008 .008 .008 .008
96.3000 | .008 .008 .008 .008 .008
96.5500 | .008 .008 .008 .008 .008
96.8000 | .008 .008 .008 .008 .008
97.0500 | .008 .008 .008 .008 .008
97.3000 | .008 .008 .008 .008 .008
97.5500 | .007 .007 .007 .007 .007
97.8000 | .007 .007 .007 .007 .007
98.0500 | .007 .007 .007 .007 .007
98.3000 | .007 .007 .007 .007 .007
98.5500 | .007 .007 .007 .007 .007
98.8000 | .007 .007 .007 .007 .007
99.0500 | .007 .007 .007 .007 .007
99.3000 | .007 .007 .007 .007 .007
99.5500 | .006 .006 .006 .006 .006
99.8000 | .006 .006 .006 .006 .006
100.0500 | .006 .006 .006 .006 .006
100.3000 | .006 .006 .006 .006 .006
100.5500 | .006 .006 .006 .006 .006
100.8000 | .006 .006 .006 .006 .006
101.0500 | .006 .006 .006 .006 .006
101.3000 | .006 .006 .006 .006 .006
101.5500 | .006 .006 .006 .006 .006
101.8000 | .006 .005 .005 .005 .005
102.0500 | .005 .005 .005 .005 .005
102.3000 | .005 .005 .005 .005 .005
102.5500 | .005 .005 .005 .005 .005
102.8000 | .005 .005 .005 .005 .005
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 81 of 138
Type.... Time vs. Volume Page 4.09
Name.... BMP 1 OUT Tag: 1 Event: 1 yr
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
Storm... SCS TP II-6 MIN Tag: 1
TIME vs. VOLUME (ac-ft)

Time | Output Time increment = .0500 hrs
hrs | Time on left represents time for first value in each row.
---------|--------------------------------------------------------------
103.0500 | .005 .005 .005 .005 .005
103.3000 | .005 .005 .005 .005 .005
103.5500 | .005 .005 .005 .005 .005
103.8000 | .005 .005 .005 .005 .005
104.0500 | .005 .005 .005 .005 .005
104.3000 | .005 .005 .005 .005 .005
104.5500 | .005 .005 .005 .004 .004
104.8000 | .004 .004 .004 .004 .004
105.0500 | .004 .004 .004 .004 .004
105.3000 | .004 .004 .004 .004 .004
105.5500 | .004 .004 .004 .004 .004
105.8000 | .004 .004 .004 .004 .004
106.0500 | .004 .004 .004 .004 .004
106.3000 | .004 .004 .004 .004 .004
106.5500 | .004 .004 .004 .004 .004
106.8000 | .004 .004 .004 .004 .004
107.0500 | .004 .004 .004 .004 .004
107.3000 | .004 .004 .004 .004 .004
107.5500 | .004 .004 .004 .004 .004
107.8000 | .004 .004 .004 .004 .004
108.0500 | .004 .004 .004 .003 .003
108.3000 | .003
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 82 of 138
Type.... Vol: Elev-Volume Page 5.01
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
USER DEFINED VOLUME RATING TABLE
Elevation Volume
(ft) (ac-ft)
---------------------
644.50 .000
645.00 .161
646.00 .538
647.00 .948
648.00 1.392
649.00 1.882
650.25 2.433
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 83 of 138
Type.... Outlet Input Data Page 6.01
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 644.50 ft
Increment = .20 ft
Max. Elev.= 650.25 ft
**********************************************
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
----------------- ---- ------- --------- ---------
Orifice-Circular OR ---> TW 644.500 650.250
Weir-Rectangular W3 ---> TW 648.250 650.250
Weir-Rectangular W2 ---> TW 648.250 650.250
Weir-Rectangular ES ---> TW 648.750 650.250
TW SETUP, DS Channel
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 84 of 138
Type.... Outlet Input Data Page 6.02
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
OUTLET STRUCTURE INPUT DATA
Structure ID = OR
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 644.50 ft
Diameter = .2500 ft
Orifice Coeff. = .600
Structure ID = W3
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.25 ft
Weir Length = 4.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
Structure ID = W2
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.25 ft
Weir Length = 4.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 85 of 138
Type.... Outlet Input Data Page 6.03
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
OUTLET STRUCTURE INPUT DATA
Structure ID = ES
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.75 ft
Weir Length = 20.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 30
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .10 cfs
Max. Q tolerance = .10 cfs
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 86 of 138
Type.... Individual Outlet Curves Page 6.04
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = OR (Orifice-Circular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall Upstream HW & DNstream TW < Inv.El
644.70 .06 Free Outfall CRIT.DEPTH CONTROL Vh= .059ft Dcr= .141ft
CRIT.DEPTH
644.90 .12 Free Outfall H =.28
645.10 .16 Free Outfall H =.47
645.30 .19 Free Outfall H =.67
645.50 .22 Free Outfall H =.88
645.70 .24 Free Outfall H =1.08
645.90 .27 Free Outfall H =1.28
646.10 .29 Free Outfall H =1.47
646.30 .31 Free Outfall H =1.67
646.50 .32 Free Outfall H =1.88
646.70 .34 Free Outfall H =2.08
646.90 .36 Free Outfall H =2.28
647.10 .37 Free Outfall H =2.47
647.30 .39 Free Outfall H =2.67
647.50 .40 Free Outfall H =2.88
647.70 .41 Free Outfall H =3.08
647.90 .43 Free Outfall H =3.28
648.10 .44 Free Outfall H =3.47
648.25 .45 Free Outfall H =3.63
648.30 .45 Free Outfall H =3.67
648.50 .47 Free Outfall H =3.88
648.70 .48 Free Outfall H =4.08
648.75 .48 Free Outfall H =4.13
648.90 .49 Free Outfall H =4.28
649.10 .50 Free Outfall H =4.47
649.30 .51 Free Outfall H =4.67
649.50 .52 Free Outfall H =4.88
649.70 .53 Free Outfall H =5.08
649.90 .54 Free Outfall H =5.28
650.10 .55 Free Outfall H =5.47
650.25 .56 Free Outfall H =5.63
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 87 of 138
Type.... Individual Outlet Curves Page 6.05
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = W3 (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.250
644.70 .00 Free Outfall HW & TW below Inv.El.=648.250
644.90 .00 Free Outfall HW & TW below Inv.El.=648.250
645.10 .00 Free Outfall HW & TW below Inv.El.=648.250
645.30 .00 Free Outfall HW & TW below Inv.El.=648.250
645.50 .00 Free Outfall HW & TW below Inv.El.=648.250
645.70 .00 Free Outfall HW & TW below Inv.El.=648.250
645.90 .00 Free Outfall HW & TW below Inv.El.=648.250
646.10 .00 Free Outfall HW & TW below Inv.El.=648.250
646.30 .00 Free Outfall HW & TW below Inv.El.=648.250
646.50 .00 Free Outfall HW & TW below Inv.El.=648.250
646.70 .00 Free Outfall HW & TW below Inv.El.=648.250
646.90 .00 Free Outfall HW & TW below Inv.El.=648.250
647.10 .00 Free Outfall HW & TW below Inv.El.=648.250
647.30 .00 Free Outfall HW & TW below Inv.El.=648.250
647.50 .00 Free Outfall HW & TW below Inv.El.=648.250
647.70 .00 Free Outfall HW & TW below Inv.El.=648.250
647.90 .00 Free Outfall HW & TW below Inv.El.=648.250
648.10 .00 Free Outfall HW & TW below Inv.El.=648.250
648.25 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.30 .14 Free Outfall H=.05; Htw=.00; Qfree=.14;
648.50 1.55 Free Outfall H=.25; Htw=.00; Qfree=1.55;
648.70 3.74 Free Outfall H=.45; Htw=.00; Qfree=3.74;
648.75 4.38 Free Outfall H=.50; Htw=.00; Qfree=4.38;
648.90 6.50 Free Outfall H=.65; Htw=.00; Qfree=6.50;
649.10 9.72 Free Outfall H=.85; Htw=.00; Qfree=9.72;
649.30 13.34 Free Outfall H=1.05; Htw=.00; Qfree=13.34;
649.50 17.33 Free Outfall H=1.25; Htw=.00; Qfree=17.33;
649.70 21.65 Free Outfall H=1.45; Htw=.00; Qfree=21.65;
649.90 26.28 Free Outfall H=1.65; Htw=.00; Qfree=26.28;
650.10 31.20 Free Outfall H=1.85; Htw=.00; Qfree=31.20;
650.25 35.07 Free Outfall H=2.00; Htw=.00; Qfree=35.07;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 88 of 138
Type.... Individual Outlet Curves Page 6.06
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = W2 (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.250
644.70 .00 Free Outfall HW & TW below Inv.El.=648.250
644.90 .00 Free Outfall HW & TW below Inv.El.=648.250
645.10 .00 Free Outfall HW & TW below Inv.El.=648.250
645.30 .00 Free Outfall HW & TW below Inv.El.=648.250
645.50 .00 Free Outfall HW & TW below Inv.El.=648.250
645.70 .00 Free Outfall HW & TW below Inv.El.=648.250
645.90 .00 Free Outfall HW & TW below Inv.El.=648.250
646.10 .00 Free Outfall HW & TW below Inv.El.=648.250
646.30 .00 Free Outfall HW & TW below Inv.El.=648.250
646.50 .00 Free Outfall HW & TW below Inv.El.=648.250
646.70 .00 Free Outfall HW & TW below Inv.El.=648.250
646.90 .00 Free Outfall HW & TW below Inv.El.=648.250
647.10 .00 Free Outfall HW & TW below Inv.El.=648.250
647.30 .00 Free Outfall HW & TW below Inv.El.=648.250
647.50 .00 Free Outfall HW & TW below Inv.El.=648.250
647.70 .00 Free Outfall HW & TW below Inv.El.=648.250
647.90 .00 Free Outfall HW & TW below Inv.El.=648.250
648.10 .00 Free Outfall HW & TW below Inv.El.=648.250
648.25 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.30 .14 Free Outfall H=.05; Htw=.00; Qfree=.14;
648.50 1.55 Free Outfall H=.25; Htw=.00; Qfree=1.55;
648.70 3.74 Free Outfall H=.45; Htw=.00; Qfree=3.74;
648.75 4.38 Free Outfall H=.50; Htw=.00; Qfree=4.38;
648.90 6.50 Free Outfall H=.65; Htw=.00; Qfree=6.50;
649.10 9.72 Free Outfall H=.85; Htw=.00; Qfree=9.72;
649.30 13.34 Free Outfall H=1.05; Htw=.00; Qfree=13.34;
649.50 17.33 Free Outfall H=1.25; Htw=.00; Qfree=17.33;
649.70 21.65 Free Outfall H=1.45; Htw=.00; Qfree=21.65;
649.90 26.28 Free Outfall H=1.65; Htw=.00; Qfree=26.28;
650.10 31.20 Free Outfall H=1.85; Htw=.00; Qfree=31.20;
650.25 35.07 Free Outfall H=2.00; Htw=.00; Qfree=35.07;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 89 of 138
Type.... Individual Outlet Curves Page 6.07
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = ES (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.750
644.70 .00 Free Outfall HW & TW below Inv.El.=648.750
644.90 .00 Free Outfall HW & TW below Inv.El.=648.750
645.10 .00 Free Outfall HW & TW below Inv.El.=648.750
645.30 .00 Free Outfall HW & TW below Inv.El.=648.750
645.50 .00 Free Outfall HW & TW below Inv.El.=648.750
645.70 .00 Free Outfall HW & TW below Inv.El.=648.750
645.90 .00 Free Outfall HW & TW below Inv.El.=648.750
646.10 .00 Free Outfall HW & TW below Inv.El.=648.750
646.30 .00 Free Outfall HW & TW below Inv.El.=648.750
646.50 .00 Free Outfall HW & TW below Inv.El.=648.750
646.70 .00 Free Outfall HW & TW below Inv.El.=648.750
646.90 .00 Free Outfall HW & TW below Inv.El.=648.750
647.10 .00 Free Outfall HW & TW below Inv.El.=648.750
647.30 .00 Free Outfall HW & TW below Inv.El.=648.750
647.50 .00 Free Outfall HW & TW below Inv.El.=648.750
647.70 .00 Free Outfall HW & TW below Inv.El.=648.750
647.90 .00 Free Outfall HW & TW below Inv.El.=648.750
648.10 .00 Free Outfall HW & TW below Inv.El.=648.750
648.25 .00 Free Outfall HW & TW below Inv.El.=648.750
648.30 .00 Free Outfall HW & TW below Inv.El.=648.750
648.50 .00 Free Outfall HW & TW below Inv.El.=648.750
648.70 .00 Free Outfall HW & TW below Inv.El.=648.750
648.75 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.90 3.60 Free Outfall H=.15; Htw=.00; Qfree=3.60;
649.10 12.84 Free Outfall H=.35; Htw=.00; Qfree=12.84;
649.30 25.29 Free Outfall H=.55; Htw=.00; Qfree=25.29;
649.50 40.27 Free Outfall H=.75; Htw=.00; Qfree=40.27;
649.70 57.41 Free Outfall H=.95; Htw=.00; Qfree=57.41;
649.90 76.46 Free Outfall H=1.15; Htw=.00; Qfree=76.46;
650.10 97.25 Free Outfall H=1.35; Htw=.00; Qfree=97.25;
650.25 113.90 Free Outfall H=1.50; Htw=.00; Qfree=113.90;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 90 of 138
Type.... Composite Rating Curve Page 6.08
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge -------------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall None contributing
644.70 .06 Free Outfall OR
644.90 .12 Free Outfall OR
645.10 .16 Free Outfall OR
645.30 .19 Free Outfall OR
645.50 .22 Free Outfall OR
645.70 .24 Free Outfall OR
645.90 .27 Free Outfall OR
646.10 .29 Free Outfall OR
646.30 .31 Free Outfall OR
646.50 .32 Free Outfall OR
646.70 .34 Free Outfall OR
646.90 .36 Free Outfall OR
647.10 .37 Free Outfall OR
647.30 .39 Free Outfall OR
647.50 .40 Free Outfall OR
647.70 .41 Free Outfall OR
647.90 .43 Free Outfall OR
648.10 .44 Free Outfall OR
648.25 .45 Free Outfall OR +W3 +W2
648.30 .73 Free Outfall OR +W3 +W2
648.50 3.57 Free Outfall OR +W3 +W2
648.70 7.96 Free Outfall OR +W3 +W2
648.75 9.25 Free Outfall OR +W3 +W2 +ES
648.90 17.09 Free Outfall OR +W3 +W2 +ES
649.10 32.77 Free Outfall OR +W3 +W2 +ES
649.30 52.48 Free Outfall OR +W3 +W2 +ES
649.50 75.45 Free Outfall OR +W3 +W2 +ES
649.70 101.24 Free Outfall OR +W3 +W2 +ES
649.90 129.57 Free Outfall OR +W3 +W2 +ES
650.10 160.20 Free Outfall OR +W3 +W2 +ES
650.25 184.61 Free Outfall OR +W3 +W2 +ES
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 91 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 1... 2.01, 3.01

----- B -----
B-POST DEV 1... 3.02
B-POST DEV 2... 3.03
BMP 1... 5.01, 6.01, 6.04, 6.08,
4.01

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:27:12 Date: 12/28/2017
Page 92 of 138

Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 1..... Tc Calcs ........................... 2.01
********************** CN CALCULATIONS *********************

A-PRE DEV 1..... Runoff CN-Area ..................... 3.01

B-POST DEV 1.... Runoff CN-Area ..................... 3.02

B-POST DEV 2.... Runoff CN-Area ..................... 3.03
*********************** POND VOLUMES ***********************

BMP 1........... Vol: Elev-Volume ................... 4.01
******************** OUTLET STRUCTURES *********************

BMP 1........... Outlet Input Data .................. 5.01
Individual Outlet Curves ........... 5.04
Composite Rating Curve ............. 5.08

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 93 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ 6 Hour Storms

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
100 5.3400 Time-Depth Curve DETENT 100 Year 6 Hour
.10 3.7220 Time-Depth Curve DETENT 10 Year 6 Hour
..2 2.2800 Time-Depth Curve DETENT 2 Year 6 Hour

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-ft
----------------- ---- ------ ---------- -- --------- -------- -------- -----------
-
A-PRE DEV 1 AREA 100 1.844 3.3500 23.47
A-PRE DEV 1 AREA 10 .755 3.4000 8.58
A-PRE DEV 1 AREA 2 .130 3.6000 .95

*A-PRE OUT PT.-2 JCT 100 1.844 3.3500 23.47
*A-PRE OUT PT.-2 JCT 10 .755 3.4000 8.58
*A-PRE OUT PT.-2 JCT 2 .130 3.6000 .95

B-POST DEV 1 AREA 100 4.278 3.1000 109.45
B-POST DEV 1 AREA 10 2.292 3.1000 59.43
B-POST DEV 1 AREA 2 .825 3.1000 22.21

B-POST DEV 2 AREA 100 .115 3.1000 2.69
B-POST DEV 2 AREA 10 .045 3.1500 .81
B-POST DEV 2 AREA 2 .006 3.5000 .05

*B-POST OUT PT.-2 JCT 100 4.385 3.2500 48.69
*B-POST OUT PT.-2 JCT 10 2.328 4.0500 5.25
*B-POST OUT PT.-2 JCT 2 .828 5.6000 .34

BMP 1 IN POND 100 4.278 3.1000 109.45
BMP 1 IN POND 10 2.292 3.1000 59.43
BMP 1 IN POND 2 .825 3.1000 22.21

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 94 of 138
Type.... Master Network Summary Page 1.02
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method

(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-ft
----------------- ---- ------ ---------- -- --------- -------- -------- -----------
-
BMP 1 OUT POND 100 4.270 3.2500 47.20 649.25 1.990
BMP 1 OUT POND 10 2.284 4.1000 5.11 648.57 1.671
BMP 1 OUT POND 2 .822 5.8500 .32 646.52 .752

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 95 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .048400 ft/ft
Mannings n .0350
Hydraulic Length 300.00 ft
Avg.Velocity 13.23 ft/sec
Segment #1 Time: .0063 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 1049.00 ft
Slope .048400 ft/ft
Unpaved
Avg.Velocity 3.55 ft/sec
Segment #2 Time: .0821 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .020000 ft/ft
Avg.Velocity .13 ft/sec
Segment #3 Time: .3332 hrs
------------------------------------------------------------------------
=========================
Total Tc: .4215 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 96 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 97 of 138
Type.... Tc Calcs Page 2.03
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 98 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil. Good 61 9.810 61.00
Woods, Class B Soil, Good 55 5.490 55.00
Impervious 98 .020 98.00
Gravel 98 .140 98.00
COMPOSITE AREA & WEIGHTED CN ---> 15.460 59.25 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 99 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Off-Site Impervious 98 .081 98.00
Off-Site Gravel, Class B Soil 98 .139 98.00
Impervious 98 1.725 98.00
Open Space, Class B Soil, Good 61 10.530 61.00
Wooded, Class B Soil, Good 55 .810 55.00
Future Gravel 98 .780 98.00
Future Impervious 98 2.070 98.00
Gravel BMP Access Road 98 .154 98.00
Synthetic Turf 98 2.239 98.00
Wetpond 98 .282 98.00
COMPOSITE AREA & WEIGHTED CN ---> 18.810 75.44 (75)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 100 of 138
Type.... Runoff CN-Area Page 3.03
Name.... B-POST DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 .310 61.00
Woods, Class B Soil, Good 55 .760 55.00
COMPOSITE AREA & WEIGHTED CN ---> 1.070 56.74 (57)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 101 of 138
Type.... Vol: Elev-Volume Page 4.01
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
USER DEFINED VOLUME RATING TABLE
Elevation Volume
(ft) (ac-ft)
---------------------
644.50 .000
645.00 .161
646.00 .538
647.00 .948
648.00 1.392
649.00 1.882
650.25 2.433
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 102 of 138
Type.... Outlet Input Data Page 5.01
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
REQUESTED POND WS ELEVATIONS:
Min. Elev.= 644.50 ft
Increment = .20 ft
Max. Elev.= 650.25 ft
**********************************************
OUTLET CONNECTIVITY
**********************************************
---> Forward Flow Only (UpStream to DnStream)
<--- Reverse Flow Only (DnStream to UpStream)
<---> Forward and Reverse Both Allowed
Structure No. Outfall E1, ft E2, ft
----------------- ---- ------- --------- ---------
Orifice-Circular OR ---> TW 644.500 650.250
Weir-Rectangular W3 ---> TW 648.250 650.250
Weir-Rectangular W2 ---> TW 648.250 650.250
Weir-Rectangular ES ---> TW 648.750 650.250
TW SETUP, DS Channel
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 103 of 138
Type.... Outlet Input Data Page 5.02
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
OUTLET STRUCTURE INPUT DATA
Structure ID = OR
Structure Type = Orifice-Circular
------------------------------------
# of Openings = 1
Invert Elev. = 644.50 ft
Diameter = .2500 ft
Orifice Coeff. = .600
Structure ID = W3
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.25 ft
Weir Length = 4.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
Structure ID = W2
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.25 ft
Weir Length = 4.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 104 of 138
Type.... Outlet Input Data Page 5.03
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
OUTLET STRUCTURE INPUT DATA
Structure ID = ES
Structure Type = Weir-Rectangular
------------------------------------
# of Openings = 1
Crest Elev. = 648.75 ft
Weir Length = 20.00 ft
Weir Coeff. = 3.100000
Weir TW effects (Use adjustment equation)
Structure ID = TW
Structure Type = TW SETUP, DS Channel
------------------------------------
FREE OUTFALL CONDITIONS SPECIFIED
CONVERGENCE TOLERANCES...
Maximum Iterations= 30
Min. TW tolerance = .01 ft
Max. TW tolerance = .01 ft
Min. HW tolerance = .01 ft
Max. HW tolerance = .01 ft
Min. Q tolerance = .10 cfs
Max. Q tolerance = .10 cfs
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 105 of 138
Type.... Individual Outlet Curves Page 5.04
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = OR (Orifice-Circular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall Upstream HW & DNstream TW < Inv.El
644.70 .06 Free Outfall CRIT.DEPTH CONTROL Vh= .059ft Dcr= .141ft
CRIT.DEPTH
644.90 .12 Free Outfall H =.28
645.10 .16 Free Outfall H =.47
645.30 .19 Free Outfall H =.67
645.50 .22 Free Outfall H =.88
645.70 .24 Free Outfall H =1.08
645.90 .27 Free Outfall H =1.28
646.10 .29 Free Outfall H =1.47
646.30 .31 Free Outfall H =1.67
646.50 .32 Free Outfall H =1.88
646.70 .34 Free Outfall H =2.08
646.90 .36 Free Outfall H =2.28
647.10 .37 Free Outfall H =2.47
647.30 .39 Free Outfall H =2.67
647.50 .40 Free Outfall H =2.88
647.70 .41 Free Outfall H =3.08
647.90 .43 Free Outfall H =3.28
648.10 .44 Free Outfall H =3.47
648.25 .45 Free Outfall H =3.63
648.30 .45 Free Outfall H =3.67
648.50 .47 Free Outfall H =3.88
648.70 .48 Free Outfall H =4.08
648.75 .48 Free Outfall H =4.13
648.90 .49 Free Outfall H =4.28
649.10 .50 Free Outfall H =4.47
649.30 .51 Free Outfall H =4.67
649.50 .52 Free Outfall H =4.88
649.70 .53 Free Outfall H =5.08
649.90 .54 Free Outfall H =5.28
650.10 .55 Free Outfall H =5.47
650.25 .56 Free Outfall H =5.63
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 106 of 138
Type.... Individual Outlet Curves Page 5.05
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = W3 (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.250
644.70 .00 Free Outfall HW & TW below Inv.El.=648.250
644.90 .00 Free Outfall HW & TW below Inv.El.=648.250
645.10 .00 Free Outfall HW & TW below Inv.El.=648.250
645.30 .00 Free Outfall HW & TW below Inv.El.=648.250
645.50 .00 Free Outfall HW & TW below Inv.El.=648.250
645.70 .00 Free Outfall HW & TW below Inv.El.=648.250
645.90 .00 Free Outfall HW & TW below Inv.El.=648.250
646.10 .00 Free Outfall HW & TW below Inv.El.=648.250
646.30 .00 Free Outfall HW & TW below Inv.El.=648.250
646.50 .00 Free Outfall HW & TW below Inv.El.=648.250
646.70 .00 Free Outfall HW & TW below Inv.El.=648.250
646.90 .00 Free Outfall HW & TW below Inv.El.=648.250
647.10 .00 Free Outfall HW & TW below Inv.El.=648.250
647.30 .00 Free Outfall HW & TW below Inv.El.=648.250
647.50 .00 Free Outfall HW & TW below Inv.El.=648.250
647.70 .00 Free Outfall HW & TW below Inv.El.=648.250
647.90 .00 Free Outfall HW & TW below Inv.El.=648.250
648.10 .00 Free Outfall HW & TW below Inv.El.=648.250
648.25 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.30 .14 Free Outfall H=.05; Htw=.00; Qfree=.14;
648.50 1.55 Free Outfall H=.25; Htw=.00; Qfree=1.55;
648.70 3.74 Free Outfall H=.45; Htw=.00; Qfree=3.74;
648.75 4.38 Free Outfall H=.50; Htw=.00; Qfree=4.38;
648.90 6.50 Free Outfall H=.65; Htw=.00; Qfree=6.50;
649.10 9.72 Free Outfall H=.85; Htw=.00; Qfree=9.72;
649.30 13.34 Free Outfall H=1.05; Htw=.00; Qfree=13.34;
649.50 17.33 Free Outfall H=1.25; Htw=.00; Qfree=17.33;
649.70 21.65 Free Outfall H=1.45; Htw=.00; Qfree=21.65;
649.90 26.28 Free Outfall H=1.65; Htw=.00; Qfree=26.28;
650.10 31.20 Free Outfall H=1.85; Htw=.00; Qfree=31.20;
650.25 35.07 Free Outfall H=2.00; Htw=.00; Qfree=35.07;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 107 of 138
Type.... Individual Outlet Curves Page 5.06
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = W2 (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.250
644.70 .00 Free Outfall HW & TW below Inv.El.=648.250
644.90 .00 Free Outfall HW & TW below Inv.El.=648.250
645.10 .00 Free Outfall HW & TW below Inv.El.=648.250
645.30 .00 Free Outfall HW & TW below Inv.El.=648.250
645.50 .00 Free Outfall HW & TW below Inv.El.=648.250
645.70 .00 Free Outfall HW & TW below Inv.El.=648.250
645.90 .00 Free Outfall HW & TW below Inv.El.=648.250
646.10 .00 Free Outfall HW & TW below Inv.El.=648.250
646.30 .00 Free Outfall HW & TW below Inv.El.=648.250
646.50 .00 Free Outfall HW & TW below Inv.El.=648.250
646.70 .00 Free Outfall HW & TW below Inv.El.=648.250
646.90 .00 Free Outfall HW & TW below Inv.El.=648.250
647.10 .00 Free Outfall HW & TW below Inv.El.=648.250
647.30 .00 Free Outfall HW & TW below Inv.El.=648.250
647.50 .00 Free Outfall HW & TW below Inv.El.=648.250
647.70 .00 Free Outfall HW & TW below Inv.El.=648.250
647.90 .00 Free Outfall HW & TW below Inv.El.=648.250
648.10 .00 Free Outfall HW & TW below Inv.El.=648.250
648.25 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.30 .14 Free Outfall H=.05; Htw=.00; Qfree=.14;
648.50 1.55 Free Outfall H=.25; Htw=.00; Qfree=1.55;
648.70 3.74 Free Outfall H=.45; Htw=.00; Qfree=3.74;
648.75 4.38 Free Outfall H=.50; Htw=.00; Qfree=4.38;
648.90 6.50 Free Outfall H=.65; Htw=.00; Qfree=6.50;
649.10 9.72 Free Outfall H=.85; Htw=.00; Qfree=9.72;
649.30 13.34 Free Outfall H=1.05; Htw=.00; Qfree=13.34;
649.50 17.33 Free Outfall H=1.25; Htw=.00; Qfree=17.33;
649.70 21.65 Free Outfall H=1.45; Htw=.00; Qfree=21.65;
649.90 26.28 Free Outfall H=1.65; Htw=.00; Qfree=26.28;
650.10 31.20 Free Outfall H=1.85; Htw=.00; Qfree=31.20;
650.25 35.07 Free Outfall H=2.00; Htw=.00; Qfree=35.07;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 108 of 138
Type.... Individual Outlet Curves Page 5.07
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
RATING TABLE FOR ONE OUTLET TYPE
Structure ID = ES (Weir-Rectangular)
--------------------------------------
Upstream ID = (Pond Water Surface)
DNstream ID = TW (Pond Outfall)
WS Elev,Device Q Tail Water Notes
---------------- --------------- --------------------------
WS Elev. Q TW Elev Converge
ft cfs ft +/-ft Computation Messages
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall HW & TW below Inv.El.=648.750
644.70 .00 Free Outfall HW & TW below Inv.El.=648.750
644.90 .00 Free Outfall HW & TW below Inv.El.=648.750
645.10 .00 Free Outfall HW & TW below Inv.El.=648.750
645.30 .00 Free Outfall HW & TW below Inv.El.=648.750
645.50 .00 Free Outfall HW & TW below Inv.El.=648.750
645.70 .00 Free Outfall HW & TW below Inv.El.=648.750
645.90 .00 Free Outfall HW & TW below Inv.El.=648.750
646.10 .00 Free Outfall HW & TW below Inv.El.=648.750
646.30 .00 Free Outfall HW & TW below Inv.El.=648.750
646.50 .00 Free Outfall HW & TW below Inv.El.=648.750
646.70 .00 Free Outfall HW & TW below Inv.El.=648.750
646.90 .00 Free Outfall HW & TW below Inv.El.=648.750
647.10 .00 Free Outfall HW & TW below Inv.El.=648.750
647.30 .00 Free Outfall HW & TW below Inv.El.=648.750
647.50 .00 Free Outfall HW & TW below Inv.El.=648.750
647.70 .00 Free Outfall HW & TW below Inv.El.=648.750
647.90 .00 Free Outfall HW & TW below Inv.El.=648.750
648.10 .00 Free Outfall HW & TW below Inv.El.=648.750
648.25 .00 Free Outfall HW & TW below Inv.El.=648.750
648.30 .00 Free Outfall HW & TW below Inv.El.=648.750
648.50 .00 Free Outfall HW & TW below Inv.El.=648.750
648.70 .00 Free Outfall HW & TW below Inv.El.=648.750
648.75 .00 Free Outfall H=.00; Htw=.00; Qfree=.00;
648.90 3.60 Free Outfall H=.15; Htw=.00; Qfree=3.60;
649.10 12.84 Free Outfall H=.35; Htw=.00; Qfree=12.84;
649.30 25.29 Free Outfall H=.55; Htw=.00; Qfree=25.29;
649.50 40.27 Free Outfall H=.75; Htw=.00; Qfree=40.27;
649.70 57.41 Free Outfall H=.95; Htw=.00; Qfree=57.41;
649.90 76.46 Free Outfall H=1.15; Htw=.00; Qfree=76.46;
650.10 97.25 Free Outfall H=1.35; Htw=.00; Qfree=97.25;
650.25 113.90 Free Outfall H=1.50; Htw=.00; Qfree=113.90;
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 109 of 138
Type.... Composite Rating Curve Page 5.08
Name.... BMP 1

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 2-REV.PPW
***** COMPOSITE OUTFLOW SUMMARY ****
WS Elev, Total Q Notes
---------------- -------- Converge -------------------------
Elev. Q TW Elev Error
ft cfs ft +/-ft Contributing Structures
-------- ------- -------- ----- --------------------------
644.50 .00 Free Outfall None contributing
644.70 .06 Free Outfall OR
644.90 .12 Free Outfall OR
645.10 .16 Free Outfall OR
645.30 .19 Free Outfall OR
645.50 .22 Free Outfall OR
645.70 .24 Free Outfall OR
645.90 .27 Free Outfall OR
646.10 .29 Free Outfall OR
646.30 .31 Free Outfall OR
646.50 .32 Free Outfall OR
646.70 .34 Free Outfall OR
646.90 .36 Free Outfall OR
647.10 .37 Free Outfall OR
647.30 .39 Free Outfall OR
647.50 .40 Free Outfall OR
647.70 .41 Free Outfall OR
647.90 .43 Free Outfall OR
648.10 .44 Free Outfall OR
648.25 .45 Free Outfall OR +W3 +W2
648.30 .73 Free Outfall OR +W3 +W2
648.50 3.57 Free Outfall OR +W3 +W2
648.70 7.96 Free Outfall OR +W3 +W2
648.75 9.25 Free Outfall OR +W3 +W2 +ES
648.90 17.09 Free Outfall OR +W3 +W2 +ES
649.10 32.77 Free Outfall OR +W3 +W2 +ES
649.30 52.48 Free Outfall OR +W3 +W2 +ES
649.50 75.45 Free Outfall OR +W3 +W2 +ES
649.70 101.24 Free Outfall OR +W3 +W2 +ES
649.90 129.57 Free Outfall OR +W3 +W2 +ES
650.10 160.20 Free Outfall OR +W3 +W2 +ES
650.25 184.61 Free Outfall OR +W3 +W2 +ES
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 110 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 1... 2.01, 3.01

----- B -----
B-POST DEV 1... 3.02
B-POST DEV 2... 3.03
BMP 1... 4.01, 5.01, 5.04, 5.08

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 16:35:48 Date: 12/28/2017
Page 111 of 138
A-PRE OUT PT.-3
A-PRE DEV 2
PRE-A2
B-POST OUT PT.-3B-POST DEV 3
POST-A3
Page 112 of 138
Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 2..... Tc Calcs ........................... 2.01

B-POST DEV 3.... Tc Calcs ........................... 2.04
********************** CN CALCULATIONS *********************

A-PRE DEV 2..... Runoff CN-Area ..................... 3.01

B-POST DEV 3.... Runoff CN-Area ..................... 3.02

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 113 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ Meck Co NC 24

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
1 2.5800 Synthetic Curve DETENT SCS TP II-6 MIN

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-
ft
----------------- ---- ------ ---------- -- --------- -------- -------- --------
----
A-PRE DEV 2 AREA 1 .287 12.4000 .96

*A-PRE OUT PT.-3 JCT 1 .287 12.4000 .96

B-POST DEV 3 AREA 1 .251 12.3000 .90

*B-POST OUT PT.-3 JCT 1 .251 12.3000 .90

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 114 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .020400 ft/ft
Mannings n .0350
Hydraulic Length 1175.00 ft
Avg.Velocity 8.59 ft/sec
Segment #1 Time: .0380 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 1136.00 ft
Slope .032600 ft/ft
Unpaved
Avg.Velocity 2.91 ft/sec
Segment #2 Time: .1083 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .015000 ft/ft
Avg.Velocity .11 ft/sec
Segment #3 Time: .3738 hrs
------------------------------------------------------------------------
=========================
Total Tc: .5201 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 115 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 116 of 138
Type.... Tc Calcs Page 2.03
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 117 of 138
Type.... Tc Calcs Page 2.04
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .020400 ft/ft
Mannings n .0350
Hydraulic Length 1175.00 ft
Avg.Velocity 8.59 ft/sec
Segment #1 Time: .0380 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 802.00 ft
Slope .034500 ft/ft
Unpaved
Avg.Velocity 3.00 ft/sec
Segment #2 Time: .0743 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .020000 ft/ft
Avg.Velocity .13 ft/sec
Segment #3 Time: .3332 hrs
------------------------------------------------------------------------
=========================
Total Tc: .4455 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 118 of 138
Type.... Tc Calcs Page 2.05
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 119 of 138
Type.... Tc Calcs Page 2.06
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 120 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 12.030 61.00
Woods, Class B Soil, Good 55 7.620 55.00
Impervious 98 .140 98.00
COMPOSITE AREA & WEIGHTED CN ---> 19.790 58.95 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 121 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Impervious 98 .220 98.00
Open Space, Class B Soil, Good 61 9.550 61.00
Wooded, Class B Soil, Good 55 7.570 55.00
COMPOSITE AREA & WEIGHTED CN ---> 17.340 58.85 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 122 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 2... 2.01, 3.01

----- B -----
B-POST DEV 3... 2.04, 3.02

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:38:30 Date: 12/21/2017
Page 123 of 138
Table of Contents i
Table of Contents
********************** MASTER SUMMARY **********************

Watershed....... Master Network Summary ............. 1.01
********************** TC CALCULATIONS *********************

A-PRE DEV 2..... Tc Calcs ........................... 2.01

B-POST DEV 3.... Tc Calcs ........................... 2.04
********************** CN CALCULATIONS *********************

A-PRE DEV 2..... Runoff CN-Area ..................... 3.01

B-POST DEV 3.... Runoff CN-Area ..................... 3.02

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 124 of 138
Type.... Master Network Summary Page 1.01
Name.... Watershed
File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

MASTER DESIGN STORM SUMMARY

Default Network Design Storm File, ID STORMS.RNQ 6 Hour Storms

Total
Depth Rainfall
Return Event in Type RNF File RNF ID
------------ ------ ---------------- -------- ----------------
100 5.3400 Time-Depth Curve DETENT 100 Year 6 Hour
.10 3.7220 Time-Depth Curve DETENT 10 Year 6 Hour
..2 2.2800 Time-Depth Curve DETENT 2 Year 6 Hour

MASTER NETWORK SUMMARY
SCS Unit Hydrograph Method
(*Node=Outfall; +Node=Diversion;)
(Trun= HYG Truncation: Blank=None; L=Left; R=Rt; LR=Left&Rt)

Max
Return HYG Vol Qpeak Qpeak Max WSEL Pond
Storage
Node ID Type Event ac-ft Trun hrs cfs ft ac-
ft
----------------- ---- ------ ---------- -- --------- -------- -------- --------
----
A-PRE DEV 2 AREA 100 2.361 3.4500 27.01
A-PRE DEV 2 AREA 10 .966 3.5000 9.94
A-PRE DEV 2 AREA 2 .167 3.7000 1.13

*A-PRE OUT PT.-3 JCT 100 2.361 3.4500 27.01
*A-PRE OUT PT.-3 JCT 10 .966 3.5000 9.94
*A-PRE OUT PT.-3 JCT 2 .167 3.7000 1.13

B-POST DEV 3 AREA 100 2.068 3.4000 25.68
B-POST DEV 3 AREA 10 .847 3.4500 9.43
B-POST DEV 3 AREA 2 .146 3.6500 1.05

*B-POST OUT PT.-3 JCT 100 2.068 3.4000 25.68
*B-POST OUT PT.-3 JCT 10 .847 3.4500 9.43
*B-POST OUT PT.-3 JCT 2 .146 3.6500 1.05

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 125 of 138
Type.... Tc Calcs Page 2.01
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .020400 ft/ft
Mannings n .0350
Hydraulic Length 1175.00 ft
Avg.Velocity 8.59 ft/sec
Segment #1 Time: .0380 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 1136.00 ft
Slope .032600 ft/ft
Unpaved
Avg.Velocity 2.91 ft/sec
Segment #2 Time: .1083 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .015000 ft/ft
Avg.Velocity .11 ft/sec
Segment #3 Time: .3738 hrs
------------------------------------------------------------------------
=========================
Total Tc: .5201 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 126 of 138
Type.... Tc Calcs Page 2.02
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 127 of 138
Type.... Tc Calcs Page 2.03
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 128 of 138
Type.... Tc Calcs Page 2.04
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
TIME OF CONCENTRATION CALCULATOR
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

------------------------------------------------------------------------
Segment #1: Tc: TR-55 Channel
Flow Area 4.5000 sq.ft
Wetted Perimeter 2.68 ft
Hydraulic Radius 1.68 ft
Slope .020400 ft/ft
Mannings n .0350
Hydraulic Length 1175.00 ft
Avg.Velocity 8.59 ft/sec
Segment #1 Time: .0380 hrs
------------------------------------------------------------------------
Segment #2: Tc: TR-55 Shallow
Hydraulic Length 802.00 ft
Slope .034500 ft/ft
Unpaved
Avg.Velocity 3.00 ft/sec
Segment #2 Time: .0743 hrs
------------------------------------------------------------------------
Segment #3: Tc: TR-55 Sheet
Mannings n .2400
Hydraulic Length 150.00 ft
2yr, 24hr P 3.1200 in
Slope .020000 ft/ft
Avg.Velocity .13 ft/sec
Segment #3 Time: .3332 hrs
------------------------------------------------------------------------
=========================
Total Tc: .4455 hrs
=========================
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 129 of 138
Type.... Tc Calcs Page 2.05
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
------------------------------------------------------------------------
Tc Equations used...
------------------------------------------------------------------------

==== SCS TR-55 Sheet Flow ==============================================

Tc = (.007 * ((n * Lf)**0.8)) / ((P**.5) * (Sf**.4))

Where: Tc = Time of concentration, hrs
n = Mannings n
Lf = Flow length, ft
P = 2yr, 24hr Rain depth, inches
Sf = Slope, %

==== SCS TR-55 Shallow Concentrated Flow ===============================

Unpaved surface:
V = 16.1345 * (Sf**0.5)

Paved surface:
V = 20.3282 * (Sf**0.5)

Tc = (Lf / V) / (3600sec/hr)

Where: V = Velocity, ft/sec
Sf = Slope, ft/ft
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 130 of 138
Type.... Tc Calcs Page 2.06
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW

==== SCS Channel Flow ==================================================

R = Aq / Wp
V = (1.49 * (R**(2/3)) * (Sf**-0.5)) / n

Tc = (Lf / V) / (3600sec/hr)

Where: R = Hydraulic radius
Aq = Flow area, sq.ft.
Wp = Wetted perimeter, ft
V = Velocity, ft/sec
Sf = Slope, ft/ft
n = Mannings n
Tc = Time of concentration, hrs
Lf = Flow length, ft

S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 131 of 138
Type.... Runoff CN-Area Page 3.01
Name.... A-PRE DEV 2

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Open Space, Class B Soil, Good 61 12.030 61.00
Woods, Class B Soil, Good 55 7.620 55.00
Impervious 98 .140 98.00
COMPOSITE AREA & WEIGHTED CN ---> 19.790 58.95 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 132 of 138
Type.... Runoff CN-Area Page 3.02
Name.... B-POST DEV 3

File.... W:\PONDPAK\16240\16240-DETENTION ANALYSIS-PT 3.PPW
RUNOFF CURVE NUMBER DATA
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

--------------------------------------------------------------------------
Impervious
Area Adjustment Adjusted
Soil/Surface Description CN acres %C %UC CN
-------------------------------- ---- --------- ----- ----- ------
Impervious 98 .220 98.00
Open Space, Class B Soil, Good 61 9.550 61.00
Wooded, Class B Soil, Good 55 7.570 55.00
COMPOSITE AREA & WEIGHTED CN ---> 17.340 58.85 (59)
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 133 of 138
Appendix A A-1
Index of Starting Page Numbers for ID Names
----- A -----
A-PRE DEV 2... 2.01, 3.01

----- B -----
B-POST DEV 3... 2.04, 3.02

----- W -----
Watershed... 1.01
S/N: C21B02A06A82
PondPack Ver. 7.5 (786c)
The Isaacs Group
Compute Time: 11:12:08 Date: 12/21/2017
Page 134 of 138
Culvert Report
Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc. Saturday, Oct 14 2017
Circular Culvert
Invert Elev Dn (ft) = 637.55
Pipe Length (ft) = 72.00
Slope (%)= 0.63
Invert Elev Up (ft) = 638.00
Rise (in)= 30.0
Shape = Circular
Span (in)= 30.0
No. Barrels = 1
n-Value = 0.012
Culvert Type = Circular Concrete
Culvert Entrance = Square edge w/headwall (C)
Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 647.50
Top Width (ft)= 0.00
Crest Width (ft) = 0.00
Calculations
Qmin (cfs)= 14.46
Qmax (cfs)= 14.46
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs)= 14.46
Qpipe (cfs)= 14.46
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 3.63
Veloc Up (ft/s) = 5.68
HGL Dn (ft)= 639.44
HGL Up (ft)= 639.29
Hw Elev (ft)= 639.87
Hw/D (ft)= 0.75
Flow Regime = Inlet Control
Page 135 of 138
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Design Drawings\Current\16240-PB.dwg, C2.0-OVERALL GP, 12/21/2017 2:36:03 PM, rrovillos, 1:1Anthony B. Cowan, P.E.Digitally signed by Anthony B. Cowan, P.E. Date: 2017.12.21 16:00:11 -05'00'Page 136 of 138
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Design Drawings\Current\16240-BMP.dwg, C2.3 PREDEVELOPED, 12/21/2017 2:53:39 PM, rrovillos, 1:1Anthony B. Cowan, P.E.Digitally signed by Anthony B. Cowan, P.E. Date: 2017.12.21 16:04:28 -05'00'Page 137 of 138
P:\Active Projects\WGM Design\Broxton Soccer Complex 16240\Engineering\Design Drawings\Current\16240-BMP.dwg, C2.4 POSTDEVELOPED, 12/21/2017 4:39:43 PM, rrovillos, 1:1Anthony B. Cowan, P.E.Digitally signed by Anthony B. Cowan, P.E. Date: 2017.12.21 16:43:28 -05'00'Page 138 of 138